JP2013200424A - Dna model teaching materia and learning method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a DNA model which enables a user to learn the principle and process of replication of DNA through simulation by demonstration and into which a message including an arbitrary long text can be encrypted and written, and a manufacturing method thereof.SOLUTION: A double helical backbone of DNA or a backbone obtained by expanding and parallelizing it is made of ropes or flexible tubes, and base pairs separable at intermediate positions are arranged on the backbone. A user can learn, through simulation by demonstration, the fundamental principle of DNA replication and the process of DNA replication including discontinuous replication due to Okazaki fragments in lagging chains by utilizing flexibility of the backbone to separate a double chain into two single chains, and a decoding table created by simulating a biological genetic code dictionary is used to encrypt an arbitrary message by a base sequence to write the message into the DNA model.

Description

  The present invention learns the basic principle and specific process of DNA (deoxyribonucleic acid) model and DNA replication by simulating demonstration, and further encrypts and writes an arbitrary message including a long sentence. In particular, it is a learning method to empirically learn the information of the encrypted DNA by creating a double helical backbone or a double parallel backbone with a rope or a flexible tube, and using the flexibility of the backbone, The present invention relates to a new DNA model teaching material and a learning method using the same, which can be separated into single strands of a book and enable simulated demonstration of DNA replication including discontinuous replication by Okazaki fragments in a lagging strand.

  In order to understand the structure of molecules and crystals in detail and three-dimensionally, molecular models and crystal models are useful. These are described in, for example, Patent Documents 1 to 4. As for DNA, various models have been conventionally produced using materials such as plastic, metal, wood, paper, etc., and are commercially available and exhibited and used as teaching materials.

  In a conventional DNA model, the components of DNA, such as sugar, phosphoric acid, base or base pair, backbone, etc., which are complexes thereof, are parts having a shape such as polyhedron, prism, sphere, cylinder, cylinder, tape, etc. They are assembled into a DNA model composed of a backbone and a base pair having a double helical structure or a double parallel structure by sequentially bonding them using an adhesive, a fitting structure, a bonding wire and the like.

  However, such an existing DNA model cannot be used as a teaching material to learn DNA replication through a simulated demonstration. Because, in order to demonstrate these in a simulated manner, it is first necessary to separate double-stranded DNA into two single-stranded DNAs. However, in the existing DNA model, each part is bonded or almost “play” is achieved. This is because it is impossible to separate the duplex because it is tightly bound in the absence of “.

  Therefore, in existing DNA models, there is only one that can replace the base pair with another base pair so that mutation and genetic manipulation can be learned by simulation, and replication can be simulated. I can't find anything.

  Moreover, it is impossible to find an existing DNA model that can encrypt a message arbitrarily determined by a learner with a base sequence. Furthermore, a method for encrypting a message and writing it in a DNA model has not been known.

JP-A-5-163766 JP-A-2004-233900 JP 2009-93204 A JP2009-93205

  The present inventor has made the possibility of the backbone by making a double helical backbone or a double parallel backbone with a rope or a flexible tube, and placing a base pair that can be separated in the middle of the conventional technology. We have developed a DNA model teaching material that can be used to analyze the principle of DNA replication and simulate the process by separating the double strand into two single strands using flexibility. It was.

  In proceeding with this research, the present inventor actually assembled a DNA model devised by participants at an educational meeting for junior and senior high school students, and the structure and production of the DNA model that junior and high school students can assemble interestingly and easily. I have been searching for the law.

  Furthermore, the present inventor learned that attendees were strongly interested in the mechanism of DNA replication during lectures on DNA in seminars for adults as well as educational meetings for middle and high school students. I realized that a large educational effect can be achieved by demonstrating the specific process of replication.

  Furthermore, the present inventor has found that middle and high school students and adults are very interested in the fact that life-related information is encoded in DNA. Therefore, a method for encrypting a message arbitrarily thought by a person who assembles a DNA model with a base sequence has been sought.

  Therefore, the present inventor has developed a DNA model suitable for practical use in the field of education. A DNA model that is suitable for practical use in the field of education is not only cheap to use and easy to process, and thus not only can be produced at a low price, but also its assembly is easy. It is desirable to be able to learn the mechanism of DNA replication through experience.

  The present invention provides a DNA model teaching material that can answer such a need. Also provided is a learning method for experientially learning about the mechanism of DNA replication using the DNA model teaching material of the present invention. Furthermore, the DNA replication learning method of the present invention provides a learning method for experientially learning DNA information encoded by a base sequence using the DNA model teaching material of the present invention.

  The DNA model teaching material of the present invention corresponds to a helical backbone composed of two helical strands composed of sugar and phosphoric acid constituting DNA, and a helical “ A double-stranded backbone / structure and a helical backbone consisting of two helical strands in this DNA are composed of two helical single-stranded backbones, and the two helical single-stranded backbones. Two "helix single-chain backbones / structures composed of two ropes or flexible tubes, paired with easily separable bonds, corresponding to the bases connected by base pair sequences It has a helical double-strand structure with a base pair / structure composed of rods or cylindrical materials that are connected to each other. Here, “• structure” represents each element of the model teaching material corresponding to each element constituting the actual DNA.

  In addition, the DNA model teaching material of the present invention corresponds to a helical backbone composed of two helical strands composed of sugar and phosphoric acid constituting DNA, and “parallel” composed of a rope or a flexible tube. A double-stranded backbone / structure and a helical backbone consisting of two helical strands in this DNA are composed of two helical single-stranded backbones, and the two helical single-stranded backbones. Two "straight single-chain backbone structures composed of two ropes or flexible tubes, paired with easily separable bonds, corresponding to the bases being linked by base pair sequences It may be provided with a parallel double-stranded structure including a base pair / structure composed of a rod or a tube-like material that joins each other.

  The DNA model teaching material of the present invention is obtained by adding the “parallel double-stranded DNA / structure” of the DNA model teaching material having the above-described parallel double-stranded structure to the two “linear single-stranded DNA / structure”. The leading strand is regarded as a “linear single-stranded DNA / structure” corresponding to the leading strand in DNA replication, and the other is regarded as a “linear single-stranded DNA / structure” corresponding to the lagging strand. “Linear single-stranded DNA / structure” having a “base / structure” sequence complementary to “Linear single-stranded DNA / structure” corresponding to, and another “linear single-stranded DNA corresponding to lagging strand”・ Add “Okazaki Fragments / Structures” corresponding to Okazaki Fragments obtained by dividing linear single-stranded DNA having “Base / Structure” sequences that bind complementarily to “Structures”. Can do.

  The learning method of the DNA replication process of the present invention uses the above-described DNA model teaching material having a helical double-stranded structure or a parallel double-stranded structure, and this “helical double-stranded backbone / structure” or “parallel double-stranded backbone”.・ "Structure" is obtained by utilizing the flexibility of this structure, two "helical single-stranded backbone structures" corresponding to two helical single-stranded DNAs or two "linear single-stranded structures". The strand backbone / structure ”is separated, and one of these two structures is regarded as a parent strand in DNA replication, and the other is regarded as a daughter strand in DNA replication. By recombining with a daughter strand having a complementary “base / structure” sequence to restore the original helical double-stranded structure or parallel double-stranded structure, the daughter-strand DNA can be obtained using the parent strand as a template. Experiencing the synthesized process It is intended to learn.

  Further, the learning method of the DNA replication process of the present invention uses two sets of DNA model teaching materials having the same “base / structure” sequence in any of the above-described DNA model teaching materials having a double-stranded structure, The model material “double-stranded backbone / structure” is separated into two “single-stranded DNA / structure” corresponding to two helical single-stranded DNAs. Is considered as the parent chain, separated into the single-stranded backbone / structure of the other DNA model teaching material and considered as two daughter chains, corresponding to the sequence of the “base / structure” on each parent chain side The original “single-stranded DNA / structure” is a combination of single strands by recombination with a “strand / structure” and a daughter strand having a complementary “base / structure” sequence. By creating two different double-stranded structures, using the parent chain as a template Daughter strand DNA may be one that experiential learning process to be synthesized.

  The learning method of the DNA replication process of the present invention uses a DNA model teaching material to which the above-mentioned “linear single-stranded DNA / structure” and “Okazaki fragment / structure” are added, and from one end of the parallel double-stranded structure to the parallel double-stranded structure. By separating the double-stranded structure into two “linear single-stranded DNA structures” corresponding to the leading strand and the lagging strand, a structure corresponding to the replication bubble in DNA replication is formed, and the structure corresponding to this leading strand “Linear single-stranded DNA / structure” is continuously bonded to the body, and “Okazaki fragment / structure” is bonded to the structure of the lagging strand one by one in the direction opposite to the leading strand. By proceeding, it is possible to empirically learn the process of discontinuous replication performed in a DNA replication bubble.

  The DNA model teaching material of the present invention includes a DNA model teaching material to which the above-mentioned “linear single-stranded DNA / structure” and “Okazaki fragment / structure” are added, and a magnet at the binding portion of “base pair / structure”. By using a combination of iron pieces attracted to it, or a combination of magnets and magnets, the pair can be easily combined and separated, and the following occurs at the replication fork at the end of the replication bubble where DNA replication occurs. The three devices that represent the three processes: (1) the process of separating the parallel double-stranded structure into the leading strand and the lagging strand; Simulate the separation process in a replication fork by obtaining two “single-stranded DNA structures” by separating them into “base structures” A double-strand structure separation device, and (2) a process in which double strands are continuously synthesized using a leading strand as a template, a structure corresponding to the leading strand and a single-stranded DNA that represents a complementary DNA single strand.・ "Structure" by connecting the two structures by the attractive force of the magnet immediately after passing through the two channels whose entrance is separated and the exit is approaching and exiting the exit of the two channels , A double-stranded replication device using the leading strand as a template to simulate the replication process in the leading strand in the replication fork, and (3) the double strand is divided into Okazaki fragments and synthesized discontinuously using the lagging strand as a template The process separates the “single-stranded DNA / structure” corresponding to the lagging strand and multiple “Okazaki fragments / structures” complementary to it. Immediately after exiting the two channel outlets through the two channels that are close to the outlets, the duplication process in the lagging chain in the replication fork is simulated by coupling both structures by the attractive force of the magnet. A replication fork simulator having a double-stranded replication device using a lagging strand to be cast as a template.

  The method for learning the DNA replication process of the present invention uses the DNA model teaching material having such a replication fork simulator to perform three processes that occur at the replication fork in DNA replication, that is, (1) a parallel double-stranded structure is converted into two A process of separating a DNA single strand, that is, a leading strand and a lagging strand, (2) a process of continuous replication of DNA that proceeds in the direction of the replication fork using the leading strand as a template, and (3) a plurality of lagging strands as templates. Okazaki fragment synthesis is individually discontinuous in the direction opposite to the leading strand, but overall the discontinuous DNA is traveling in the same direction as the leading strand, ie in the same direction as the replication fork. The process of replication can be learned experientially.

  According to the genetic information code learning method of the present invention, a single DNA model is obtained by encrypting an arbitrary message with a sequence of “base pairs / structures” using a decryption table created by imitating a genetic decryption table of a living body. By encrypting a message using the DNA model teaching material according to any one of claims 1 to 6 which can be written in, it is possible to learn genetic information encryption experientially. is there

  Further, the genetic information code learning method of the present invention divides an arbitrary message, encrypts it with a base sequence using the decryption table, and writes it into a plurality of DNA models written in claim 1 or 2, By connecting them, DNA model teaching materials that make it possible to encrypt and write long messages into one model, and to encrypt genetic information by dividing and encrypting long messages using it It can be learned experientially.

  In the DNA model teaching material of the present invention, a flexible polyurethane rope or tube can be preferably used as the backbone / structure. It has been found that polyurethane ropes or tubes are readily available, flexible, and have excellent properties as materials for use in the present invention, such as forming a helical structure when heat-treated.

  With the DNA model of the present invention, from the basic principle that DNA replication is performed using the parent strand as a template, a specialized DNA replication process, that is, continuous replication performed in a replication bubble and discontinuity due to Okazaki fragments It became possible to learn the process of automatic duplication through simulated demonstrations. In addition, in the conventional DNA model, it was only possible to learn mutation and gene manipulation by substituting at most base pairs. However, in the DNA model of the present invention, if it is only possible to learn mutation and genetic manipulation by substituting base pairs. First, it is made possible to learn the DNA replication phenomenon from experience through simulated demonstrations over a wide range from the basic level to the professional level.

It is the figure which showed typically one Embodiment of the DNA model teaching material which has a helical double stranded structure of this invention. It is the figure which showed typically the DNA model teaching material which has a parallel double stranded structure which is other embodiment of this invention. It is the figure which showed typically one Embodiment of the "base pair and structure" corresponding to the base pair of the DNA model used by this invention. As an embodiment of the present invention, a state in which a front-opening type crimp terminal is attached to the tip of a “base pair / structure” in order to attach the “base pair / structure” to the “backbone / structure” is schematically illustrated. FIG. In order to clearly show complementary binding between base tubes or base rods as “base / structure”, a specific example in which the cross sections of the A / T base pair and G / C base pair are different is schematically shown. It is a figure. It is the figure which showed typically about the method of demonstrating the principle in which DNA replication is performed by using one DNA model teaching material which has the helical double stranded structure of this invention, and using a parent chain as a template. It is the figure which showed typically the method which shows the principle by which DNA replication is performed by using one DNA model teaching material which has a parallel double stranded structure of this invention, and using a parent chain as a template by a simulated demonstration. It is the figure which showed typically the method of demonstrating the principle in which semi-conservative replication of DNA is performed using a parent chain as a template using two DNA model teaching materials which have the helical double stranded structure of this invention. . It is the figure which demonstrated typically the area | region where DNA replication is performed, ie, a replication bubble, and the replication fork of the both ends. It is the figure which demonstrated typically the continuous replication on the leading strand in the DNA replication bubble, and the discontinuous replication by the Okazaki fragment on a lagging strand. Schematic method of demonstrating continuous replication on leading strand and discontinuous replication by Okazaki fragment on lagging strand using DNA simulator teaching material with replication simulator structure and replication fake simulator according to the present invention FIG.

  A “backbone / structure” corresponding to the DNA backbone is a rope or a flexible tube, and a “base pair / structure” corresponding to a DNA base pair is a plastic base pair. The helical double-stranded DNA model schematically shown in FIGS. 1 and 2, respectively, and the parallel double-stranded DNA model stretched from this were produced. In these models, the flexibility of the “backbone / structure” was used to separate the double strands into two single strands so that the basic principles of DNA replication can be learned through simulated demonstrations. . In addition, the detailed DNA replication process including continuous replication in the leading strand and discontinuous replication by the Okazaki fragment in the lagging strand as described later can be learned through simulated demonstrations.

  The DNA model teaching material having a double helical structure of the present invention is obtained by heating at a temperature equal to or higher than the softening point of the soft polyurethane in a state where two soft polyurethane ropes are wound around a cylindrical template. I was able to. However, the method for producing the double helical backbone model is not limited to this.

  The DNA model teaching material having a helical double-stranded structure schematically shown in FIG. 1 has two ropes 12a and 12b in a helical shape corresponding to a double helical backbone of DNA. In addition, the base tubes 14a and 14b are linked to correspond to the DNA base pairs and the two ropes are cross-linked, and the base tube pair 14 as the “base pair / structure” is arranged and arranged. Is. In addition, the iron strip 16 is fixed to the “valley bottom” portion of the spiral of the two ropes 12a and 12b, and this model teaching material can be attached to the base by attracting the iron piece 16 to the magnet 20 fixed to the base 18. It can be fixed.

  Further, as shown in FIG. 2, the DNA model teaching material having a parallel double-stranded structure is configured by arranging two linear ropes 12c and 12d in parallel, corresponding to the two DNA backbones. Is a “backbone / structure”, and a “base pair / structure” 14 consisting of base tubes that can be resolved by separating them in the middle, corresponding to the base pairs of separable DNA. Arranged.

  As a “base pair / structure” according to an embodiment of the present invention, the following structure was manufactured. First, the bases corresponding to the four bases of adenine, thymine, guanine and cytonin, usually abbreviated as A, T, G, and C, are made of plastic bases having four colors of red, yellow, green and blue, respectively. Corresponding to the tube. As shown in FIG. 3a, base cylinders 25, which are complementary bases, that is, “base pairs / structures” of a combination of red A and yellow T and green G and blue C, A base cylinder 25a and a base cylinder pair 25b having a joint 24 of a so-called bamboo shoot structure 22 for fixing, and a base cylinder 25c and 25d using a magnet 26 and an iron piece 28 attracted thereto as shown in FIG. 3b. Base tube pair 25 was made as a “base pair / structure”.

  As shown in FIG. 4, an aluminum tip-open crimp terminal 30 is fixed to the end of the base cylinder pair 25 formed by the two base cylinders 25a and 25b, and the U-shaped crimp terminal is fixed. A rope corresponding to the backbone was sandwiched and fixed at the open end. By adjusting the balance between the open ends and the outer diameter of the rope corresponding to the DNA backbone, the base pair is rotated with respect to the backbone rope to adjust the direction of the base pair 25 to the desired direction. In addition, it was found that the position of the base tube pair can be maintained without shifting even if an operation for simulating the DNA replication process is performed by separating and recombining the pair.

  Furthermore, since the base pair fixed using the front-opening type crimp terminal 30 can be easily removed and exchanged with other base tube pairs, mutation and genetic manipulation can be learned through simulated demonstrations.

  In addition, the shape of the base cylinder which is an element corresponding to the base pair and the method of coupling are not limited to the above-described methods. That is, an element having a shape such as a prism or an ellipse can be used as a base rod instead of a cylindrical shape. In addition, the base tube can be coupled using a hook, snap, inset structure, or the like, instead of the bamboo structure 22 or the magnet 26 shown in FIGS. 3 (a) and 3 (b). Further, as shown in FIG. 5 (a), the A base tube 25A and the T base tube 25T corresponding to the A / T base pair, and the G base tube 25G and the C base tube corresponding to the G / C base pair. The angle between the contact surface of the pair of 25C and the axis of the base pair is a right angle 29a, 29b or other angles 29c, 29d, and as shown in FIG. , 29g, and 29h can clearly show complementary binding between bases. Similarly, the “backbone / structure” rope corresponding to the DNA backbone may be, for example, a flexible tube in addition to the rope.

  As shown in FIG. 6, the helical double-stranded DNA model teaching material previously shown in FIG. 1 is pulled away from the pedestal fixed through a magnet, and as shown in FIG. The two ropes 12a and 12b corresponding to the DNA backbone are unraveled from the left end, and as shown in (c) of the figure, it is a single-stranded backbone / structure corresponding to two single-stranded DNAs. It can be separated into two ropes 32 and 34. Corresponding to the fact that the two single-stranded DNAs have a base sequence, the two single-stranded ropes are provided with the sequences of base tubes 14a and 14b. Therefore, if this model teaching material is used, the principle of DNA replication can be demonstrated in a simulated manner. That is, the rope 32 which is a single-stranded backbone / structure corresponding to one single-stranded DNA obtained by separation is first used as a parent-strand rope corresponding to the parent strand. In the living body, the parent chain is used as a template and atoms are bonded onto it to replicate the daughter chain. Here, the rope 34 as a single-chain backbone / structure corresponding to the other single-chain backbone is used here. A single rope corresponding to the daughter chain is connected to the rope 32 of the parent chain corresponding to the parent chain in order from the end to form a double-stranded backbone / structure. That is, as shown by the arrow in FIG. 6, the reverse process of (c) → (b) → (a) is followed. By doing this, the principle of DNA replication performed using the parent chain as a template can be learned.

  In addition, if the DNA model teaching material having the parallel double-stranded structure shown in FIG. 2 is used, it is not necessary to unravel the spiral. As shown in FIG. Has been obtained. In this case, as shown in FIG. 5B, two linear single-stranded DNAs / structures in which “base pairs / structures” are arranged on each of the two ropes 37, 38 from the left end are formed. After the separation, as shown in FIG. 5C, the separation can be completed and completely separated into two linear single-stranded DNA / structures. By following this process in the reverse order of (c) → (b) → (a), a single chain in which “base pair / structure” 14c is arranged on rope 37 as “linear single chain backbone / structure” A single-stranded DNA in which “base pair / structure” 14d is arranged on a rope 38 as a “linear single-stranded backbone / structure” having a base sequence complementary to this parent strand, using DNA as a template, ie, a parent strand As in the previous case, the principle of DNA replication can be learned from this.

  Furthermore, by using two identical DNA models having a helical double-stranded structure or a parallel double-stranded structure, semi-conservative replication of DNA can be simulated. That is, for one of the two DNA models of the helical double-stranded structure shown in FIG. 8 (a), this double-stranded structure is converted into two “single-stranded DNAs” as shown in FIG. 8 (b). Separated into “structures” and made them both daughter chains. The other model is also separated into two “single-stranded DNA structures” as shown in (b ′) of FIG. Next, daughter strands complementary to each parent strand are bound to obtain two “double-stranded DNA / structure” as shown in FIG. The same demonstration can be performed using a DNA model teaching material with two parallel structures.

  In DNA, binding only proceeds in the 5 ′ → 3 ′ direction of the structure, ie, in the 3 ′ → 5 ′ direction of the template DNA, so DNA replication occurred in the region where replication occurs, ie, in the replication bubble. The two linear DNAs, that is, the leading strand and the lagging strand, proceed by different processes. In particular, the lagging strand is discontinuous in such a way that the pieces that are split into Okazaki fragments and joined in opposite directions are joined together. Duplication is done. The present invention provides a method for simulating and learning such a process using a DNA model teaching material. The main points necessary for this are described below.

  In DNA replication, as shown in FIG. 9, a base pair is cleaved starting from one point of the double helical structure, that is, the replication origin 40, the double helix is released, and two linear DNAs are expanded. A duplicate bubble 42 is created. The structure at both ends of the duplication bubble 42 is called duplication fork 46. The replication fork 46 proceeds to the left and right as indicated by arrows in the figure, and the replication bubble spreads, while replication proceeds using two single-stranded DNAs as a parent chain, that is, a template.

  Here, assuming that the upper single-stranded DNA has a structure of 3 ′ → 5 ′ from left to right, replication in the right half region of the replication bubble 42 will be considered. In the upper leading strand 48, the 3 ′ → 5 ′ direction of this single strand, which is a template, coincides with the rightward direction in which the replication fork advances, as shown by the white arrow 49 at the top of FIG. A single-stranded DNA 48 'having a complementary base sequence is formed, and the replication proceeds continuously following the progress of the fork.

  On the other hand, in the lower lagging strand 50, the template has a structure of 5 '→ 3' in the right direction as opposed to the upper single strand, so replication cannot occur in the right direction in which the replication fork advances. Therefore, as indicated by the arrow 51 in FIG. 10, Okazaki fragments 52a, 52b,... Are bound one by one in the left direction opposite to the direction in which the replication fork advances, that is, in the 3 ′ → 5 ′ direction of the template DNA. And duplication is done. When the entire movement of the Okazaki fragments connected is viewed macroscopically, the replication proceeds discontinuously in the right direction as indicated by a large arrow 49 '.

  In the left half of the replication bubble, the replication fork advances from right to left as opposed to the right half, so that the upper single strand becomes a lagging strand and discontinuous replication occurs, and the lower single strand becomes a leading strand and is continuous. Duplication is done.

  The principle of DNA replication in such a replication bubble can be simulated in the following manner using the DNA model teaching material having the double parallel structure of the present invention. That is, in the DNA model teaching material having a double parallel structure, a linear DNA model complementary to one of two linear DNAs and a linear DNA having a complementary base sequence on the other are divided into a plurality of pieces. A DNA model teaching material was constructed by adding a model in which the single-stranded backbone / structure corresponding to the Okazaki fragment was divided into multiple pieces made of the same material as the single-stranded backbone / structure. In this DNA model teaching material, a rope is used corresponding to the backbone, a plastic cylinder is used corresponding to the base, and a combination of a magnet and an iron piece is used for binding the base pair to facilitate the release of the pair. Using.

  In DNA replication, the left end of the double structure shown in FIG. 10 is regarded as a replication base point, from which the base-pair bond is released to expand the double parallel structure, and the right half of the replication bubble is created. In the upper “leading strand / structure” 48, single-stranded DNA 48 ′ is continuously bound in the right direction from the origin of replication. In the lower “lagging chain / structure” 50, connect the first “Okazaki fragment / structure” 52a from the middle of the lagging chain in the direction from right to left so that the connection ends at the origin of replication. Let After that, the second “Okazaki fragment / structure” 52b is coupled so that the coupling ends at the end of the first Okazaki fragment. In the same way, all the “Okazaki fragments / structures” are joined one by one and the replication fork is extended to the right end to complete discontinuous replication.

  A replication fork simulator simulating the replication fork shown in FIG. 11 is provided in the DNA model teaching material of the present invention, and a double strand synthesis using a leading strand as a template together with a single strand backbone / structure having a base sequence complementary thereto. By providing and using the apparatus 70, the above-described continuous replication and discontinuous replication processes can be simulated in the following manner.

  The replication fork simulator simulates the function of a fork in DNA replication. As shown in FIG. 11, a double strand separator 60, a double strand synthesizer 70 using a leading strand as a template, and lagging. A double chain synthesizer 80 using a chain as a template is provided. First, as shown in FIG. 11 (a), in the replication process, two backbones are formed corresponding to the fact that base pair binding in DNA is eliminated and two single-stranded DNAs are generated.・ The magnetic coupling by the base pair pair magnet of the “base pair / structure” that binds the structure is eliminated by the tip 60a of the block of the double-strand separation device, which corresponds to the leading strand and the lagging strand It is divided into two single-chain backbone / structure ropes. Next, the single-stranded backbone / structure rope on the side corresponding to the leading strand is composed of a single-stranded backbone / structure rope having a complementary “base pair / structure” sequence and the leading strand as a template. Pass through heavy chain synthesizer 70. This double-stranded synthesizer 70 using the leading strand as a template has two channels with the entrance separated and the exit approached. It is formed into a “double-stranded backbone / structure”. On the lagging strand side, another “single-chain backbone / structure” rope 50A corresponding to the lagging strand is connected to the Okazaki fragment by the double strand synthesizer 80 using the lagging strand as a template. By passing through the double strand synthesizer 80 using the lagging strand as a template together with the ropes 52A, 52B,... Of the “fragment / structure”, discontinuous bonds are sequentially formed in the same manner as the synthesizer described above. As a result, a “double-stranded backbone / structure” is formed.

  In an actual living body, there are a large number of replication apparatuses composed of various proteins. Here, continuous replication and discontinuous replication proceed simultaneously by consolidating them into the above three apparatuses. The mechanism is easily understood. In addition, the functions of these three devices are actually performed at a single point called the replication fork, but here, by installing the three devices at a remote location, the functions become easier to see and help to understand them. Yes.

  A demonstration of DNA replication using a DNA model teaching material equipped with a replication fork simulator is performed as follows. First of all, two parallel base tubes having a base tube pair 25 of “base pair / structure” which can be easily separated and combined using the magnet 26 and the iron piece 28 shown in FIG. A rope 48A as a “single-stranded DNA / structure” corresponding to two single-stranded DNAs by passing a strand-structured DNA model teaching material through a double-strand separation device 60 as shown in FIG. Separate to 50A. The rope 48A as a “single-stranded DNA / structure” corresponding to the upper leading strand thus obtained, and the rope 48′A as a “single-stranded DNA / structure” having a complementary base tube sequence Then, the double strand synthesizer 70 in the leading strand is inserted into the double strand synthesizer 70 and pulled together to the left to obtain a double stranded backbone / structure corresponding to DNA replication continuously.

  Next, the “single-stranded DNA / structure” 50A corresponding to the lower lagging strand is folded after exiting the double-strand separator 60, and this “single-stranded DNA / structure” 50A is added to the lagging strand. The double strand synthesizer 80 is inserted together with a short piece 52A of “Okazaki Fragment / Structure” corresponding to the first Okazaki fragment, and joined together by pulling them together to the left. When the binding of the short piece 52A of the “Okazaki fragment / structure” corresponding to the first Okazaki fragment is completed and the state shown in FIG. 11b is obtained, the “single-stranded DNA / structure” 50A corresponding to the lagging strand is removed from the channel. Take out and pull the rope 50A corresponding to the lagging chain to the right to remove the deflection, resulting in the state shown in FIG. 11c. Then, a short piece 52B of “ru single-stranded DNA / structure” corresponding to the second Okazaki fragment is inserted into the double-stranded synthesizer 80 in the lagging strand, and this “single-stranded DNA / structure” 50A corresponding to the lagging strand is inserted. Pull them to the left together to join them together. After that, the same process is repeated, and the “single-stranded DNA / structure” short pieces 52A, 52B,... As “Okazaki fragments / structures” corresponding to all Okazaki fragments one by one corresponding to the lagging strands. • Combine with structure 50A to complete discontinuous replication.

  Furthermore, in the present invention, a genetic code decoding table of a living body, that is, a code table imitating a code table that designates one amino acid by a codon (three base sequences) is arbitrarily created. Using this, it was possible to write an arbitrary message encrypted with the base pair sequence of the DNA model teaching material.

  There are 4 × 4 × 4 = 64 codons, and therefore 64 types exist, so 64 types of characters, phonetic symbols, and the like can be encrypted by the codons. As an example, a cryptanalysis table in which 50 Japanese syllables and 14 phonetic symbols are encrypted is arbitrarily prepared and shown in Table 1. A similar cryptanalysis table can be created for the English alphabet and its phonetic symbols. The English alphabet has only 23 characters, so it can be created without using all 64 codons including the phonetic symbols. it can. Therefore, in the case of using English text, a plurality of codons may be associated with one character or a phonetic symbol, or only a part of the codons may be used, as in the case of a biological genetic code decoding table.

  At an educational meeting, etc., all participants are divided into individual or group to create multiple DNA model teaching materials with the same structure, and then divide and write long messages on them and connect them together to form one DNA model teaching material. If this is possible, the participants will have a stronger sense of solidarity and a higher educational effect. In the present invention, there is provided a method of connecting a DNA model teaching material—which will be referred to as an “element model teaching material” in the future—to make a single DNA model teaching material and encrypting and writing a long message.

  Since DNA has 10 base pairs per pitch and the codon consists of 3 bases, it is divided into element model teaching materials with the same structure and therefore the same number of base pairs, and they are written as cipher text. The number of base pairs in the element model teaching material must be an integer multiple of 30 (= 10 × 3). However, even DNA model teaching materials having 30 base pairs as well as 60 and 90 require a long time to assemble, and are not preferable for use in educational gatherings. Therefore, in the present invention, a method of dividing and encrypting a message into a plurality of element models having 20 base pairs, that is, a DNA model teaching material that can be assembled in a relatively short time and that looks good as a DNA model teaching material, is devised. did. The specific method will be described later with reference to an embodiment.

(Preparation of DNA model teaching materials with double helical structure that can demonstrate the basic principle of DNA replication)
A DNA model teaching material with a double helical structure was made from a soft polyurethane with a light red transparent and light green transparent fluorescent color, and a “backbone / structure” made of a rope with a circular cross section of 4 mm in diameter. The “base pair / structure” corresponding to the base pair having the joint with the “bamboo structure” shown in FIG. For this purpose, first, wrap the two flexible polyurethane ropes described above around a cylindrical jig with a template attached, and use a general-purpose microcomputer-controlled oven toaster to set the scale at 105 ° C and heat for 3 minutes. Established a double helical backbone structure. Base pairs (length: 52 mm) with polystyrene cylinders (outer diameter 6 mm, inner system 3.5 mm, length 26 mm) with red, yellow, green and blue colors respectively corresponding to the bases of A, T, G and C ), And as described in the column [0032], the base pair is formed by sandwiching a flexible polyurethane rope with a double helical backbone at the tip of a pre-open crimp terminal fixed to the end of each base pair.・ Fixed to “structure”.

  In an actual DNA molecule, 10 base pairs per helical pitch are arranged in a direction perpendicular to the double helical axis and inclined by 18 degrees from the direction toward the helical axis, and a main groove and a minor groove are formed in the helical axis direction. ing. However, the main purpose of the present invention is not to learn the structure of DNA but to learn the principle and process of replication, so that the structure is simplified and the pair of base tubes passes through the central axis of the double helical rope. Therefore, the structure has no distinction between the main groove and the sub-groove. This facilitates assembly by the learner and simplifies the processing of the model teaching material set, thereby reducing production costs.

  In this example, the diameter of the double helical structure (the diameter of the cylindrical jig inscribed in the backbone) was 53 mm, the length of one helical pitch was 100 mm, that is, the pitch between adjacent base pairs was 10 mm.

In order to encrypt a 7-character message, the number of base pairs is set to 7 × 3 = 21. As shown in FIG. 1, iron pieces (10 × 10 × 1 mm ³⁾ are formed on four “valley bottoms” of the double helical backbone. ) Can be attached and removed using a neodymium magnet (10 x 10 x 1 mm ³ ) bonded to an acrylic base (245 x 30 x 3 mm ³ ) via a nickel ring (inner diameter 4 mm) Fixed in a stable state

In the present example, the 7-character message “Life of Life” was encrypted as shown in Table 2 using the decryption table of Table 1, and written with the base sequence on the light red soft polyurethane rope side. However, Table 2 was attached to the assembly kit, and a table with blanks in the first and second lines of Table 2 was attached as a work table in order to encrypt a message arbitrarily considered by the assembler.

  In the DNA model teaching material prepared in this example, as shown in FIG. 6, the double helical structure is separated from the pedestal and separated into two single-stranded DNAs, and DNA replication is performed using the parent chain as a template. The principle can be demonstrated in a simulated manner.

(Production of a DNA model teaching material having a double parallel structure capable of demonstrating the basic principle of DNA replication)
A DNA model having a double parallel structure, which is the same as that of Example 1 except that the double helical structure was replaced with a double parallel structure in the DNA model having the double helical structure, was the same. Since generally available soft polyurethane ropes are coiled and curved, the same conditions as described in Example 1 are applied to the same two-colored flexible polyurethane ropes as described in Example 1. And used by heat molding in a straight line. As in Example 1, the message was encrypted and entered in the model with 21 base sequences as described in Table 2.

  Since the DNA model prepared in this example can separate double parallel DNA into two single-stranded DNAs, the principle of DNA replication performed using a parent strand as a template as shown in FIG. 7 and described above is shown. be able to.

(Preparation of a DNA model teaching material with a double parallel structure that can simulate the principle of DNA replication including discontinuous replication in the lagging strand)
A set of DNA model teaching materials having a double parallel structure described in Example 2 with a linear DNA complementary to one linear DNA of the double parallel structure and an Okazaki fragment complementary to the other. A DNA model teaching material was constructed. The Okazaki fragment was obtained by dividing a linear DNA consisting of 21 base pairs into 3 parts and having 7 bases.

  Using this model teaching material set, as shown in FIG. 10 and already explained in the section [0041], the right half of the duplication bubble is created to produce continuous replication in the leading strand and discontinuous replication by Okazaki fragments in the lagging strand. You can learn by demonstrating the principle.

(In combination with a replication fork simulator, a DNA model that can simulate the DNA replication process including discontinuous replication in the lagging strand)
Red and green soft vinyl chloride tubes (outer diameter 4 mm, inner diameter 2 mm, length 420 mm) are used to form a double parallel backbone, as shown in Fig. 3b. Neodymium magnets (4 mmφ × 2 mm) and iron pieces (4 mmφ × 1 mm) and 21 base pairs of the type that are bonded with a pitch interval of 10 mm were arranged to prepare a DNA model having a double parallel structure. As in Example 3, a linear DNA complementary to one linear DNA of this DNA model and an Okazaki fragment complementary to the other were added, and further shown in FIG. 11 and previously described in the [0046] column. A set was also made with the duplicate fork simulator.

  In this embodiment, unlike Embodiments 1 to 3, the use of a vinyl chloride tube instead of a soft polyurethane rope is more flexible than the former, so that the folding and folding performed by a replication fork simulator is performed. This is to facilitate the operation. Further, the length of the base pair was set to 20 mm, which was shorter than the value (53 mm) in Examples 1 to 3, thereby facilitating the operation using the replication fork simulator.

  Duplicate fork simulator, as shown in Fig. 11a, consists of a double-strand separation device consisting of "mountain" blocks, both made of plastic, on a flat plastic substrate and straight and curved channels Two double chain synthesizers 70 and 80 were fixed and produced. The inner width of each channel of the duplex synthesizer was 15 mm, the height was 10 mm, the length was 20 mm, and an upper lid that could be opened and closed with a hinge was attached.

  Using the DNA model teaching material prepared in this example, the process of continuous replication in the leading strand in the replication bubble and discontinuous replication by the Okazaki fragment in the lagging strand by the method already shown in FIG. 11 and described in the column [0046] Can be learned experientially through demonstrations.

  Furthermore, at the end of this process, that is, when a complementary single strand is bound to the end of the double strand, a so-called telomere is formed at the end of the DNA by exploring the following: Can learn to. That is, replication on the template DNA is performed by first binding the primer RNA onto the DNA single strand that is the template, and then decomposing the primer RNA while the DNA polymerase extends the DNA from the primer RNA. However, at the end of DNA, there is a portion that cannot be replicated because DNA polymerase cannot degrade the primer RNA at the end. To avoid problems caused by this, telomeres are formed at the ends of the chromosomal DNA.

(Manufacture of DNA model with double helical structure in which long messages are divided and encrypted into multiple models)
In this example, as described above, from the viewpoint of assembly time and appearance, a message is encrypted and written in a DNA model in which element models having two helical pitches, that is, 20 base pairs are connected.

  In the DNA model having the double helical structure described in Example 1, eight element models were prepared by changing the number of base pairs from 21 to 20 which is the number of base pairs per pitch, and connected as follows. A single DNA model was constructed. In other words, all element model pedestals are fixed to a piece of wood having the same width (30 mm) as the element model pedestal with adhesive tape, and the ends of the backbones of adjacent element models are covered by transparent silicon tubes. . The “linked” DNA model produced by this method has the advantage that it can be separated into element models and brought back to the participant after completion by all participants at an educational meeting or the like.

  As a message to be encrypted, we adopted Article 5 of the Children's Charter, that is, “Shin no Shi” is swiftly sympathized and struck, and he will be struck by its morals. It was divided into models and encrypted. Since this message is composed of 50 characters (including phonetic symbols, etc.), it was encrypted with an array of 150 (= 50 × 3) base pairs and divided into 8 element models. However, since one element model has 20 base pairs, 6 characters are encrypted with 18 base pairs, and “remaining 2 base pairs” are shown in Table 3, Table 4, and Table 5, respectively. Coordinated with the “remaining two base pairs” of the element model connected before and after each element model. That is, the last two base pairs of the first element model and the first one base pair of the second element model constitute a codon, and the last one base pair of the second element model and the first two bases of the third element model Codons were formed in pairs. For the fourth and subsequent element models, the same method was used to encrypt and fill in 20 characters for each three element model with 60 base pairs.

  Since the DNA model obtained by ligation has a total of 160 base pairs, there will be 160-150 = 10 base pairs left in the last connected element model, so this is all blank (space). The codon to represent.

  According to the present invention, since a learner can not only assemble a DNA model but also encrypt and write a message that he / she thought with a base sequence, it can give a strong interest and a high willingness to learn.

  Furthermore, it is possible to create a single DNA model by connecting encrypted element models by dividing long messages, so that participants' awareness of solidarity can be increased at educational meetings and the like.

  The DNA model of the present invention is easy to assemble, and the materials used are inexpensive and easy to process, and therefore can be produced at a low price.

12a, 12b, 12c, 12d ...... Rope as "helene / structure", 14 ... Base tube pair as "base bear / structure", 14a, 14b ... Base tube as "base / structure" , 16 ... Iron piece, 18 ... Pedestal, 20 ... Magnet, 22 ... Bamboo child structure, 24 ... Joint, 25 ... Base-cylinder pair as "base pair / structure", 25a, 25b, 25c, 25d , 25A, 25T, 25G, 25C: Base tube as "base / structure", 26 ... magnet, 28 ... iron piece, 29a, 29b ... right angle contact surface, 29c, 29d ... non-right angle Contact surface, 29e, 29f, 29g, 29h .. Contact surface in the relationship between the key and the keyhole, 30 ... Pre-opening type crimp terminal, 32, 34 ... Rope that is a single chain backbone / structure, 37 ... Straight single chain back Rope (parent chain) as an "on-structure", 38 ... Rope (daughter chain) as a "straight single-chain backbone / structure", 40 ... Replication origin, 42 ... Replication bubble, 46 ... Replication Fork, 48 ... leading strand, 48A ... single-stranded backbone / structural rope corresponding to the leading strand, 48 '... single-stranded DNA, 49 ... arrow indicating binding direction, 50 ... lagging strand, 50A ...... Rope corresponding to the lagging chain, 51. Arrow indicating the binding direction in the Okazaki fragment, 52a, 52b .... Okazaki fragment, 52A..Rope as "Okazaki fragment / structure", 60 ... Double chain Separator, 60a... Block tip, 70... Double strand synthesizer in leading strand, 80... Double strand synthesizer in lagging strand.

Claims (11)

Corresponds to a helical backbone composed of two helical strands composed of sugar and phosphoric acid that constitutes DNA, a “helical double-stranded backbone / structure” composed of a rope or flexible tube When,
A helical backbone composed of two helical strands in this DNA is composed of two helical single-stranded backbones, and these two helical single-stranded backbones are linked by a base pair sequence. A rod or tube that connects two “helical single-chain backbones / structures” that consist of two ropes or flexible tubes that are paired with easily separable bonds DNA teaching material with a helical double-stranded structure, comprising a “base pair / structure” made of a material in the shape of a ring. "Parallel double-stranded backbone / structure" composed of a rope or flexible tube, corresponding to a helical backbone composed of two helical strands composed of sugar and phosphoric acid constituting DNA,
A helical backbone composed of two helical strands in this DNA is composed of two helical single-stranded backbones, and these two helical single-stranded backbones are linked by a base pair sequence. A bar or tube that connects two “straight single-chain backbones / structures” that consist of two ropes or flexible tubes that are paired with easily separable bonds A DNA model teaching material with a parallel double-stranded structure with a “base pair / structure” composed of a material in the shape of a tube. 3. The DNA model teaching material according to claim 2, wherein the “parallel double-stranded backbone / structure” of the DNA model teaching material having the parallel double-stranded structure is further separated into two “linear single-stranded backbone / structure”. One of them is regarded as a “linear single-stranded backbone / structure” corresponding to the leading strand in DNA replication, and the other is regarded as a “linear single-stranded backbone / structure” corresponding to the lagging strand. “Linear single-chain backbone / structure” having a “base / structure” sequence complementary to “single-chain backbone / structure”,
Okazaki fragment obtained by dividing a linear single-stranded DNA having a sequence of “base / structure” that complementarily binds with another “linear single-stranded backbone / structure” corresponding to the lagging strand. DNA model teaching materials with “Okazaki fragment / structure” added to   Using the DNA model teaching material having a helical double-stranded structure or a parallel double-stranded structure according to claim 1 or 2, this "helical double-stranded backbone / structure" or "parallel double-stranded backbone / structure" Separated into two “helical single-stranded backbones / structures” or two “linear single-stranded backbones / structures” corresponding to two helical single-stranded DNAs. By making one of these correspond to the parent strand in DNA replication and the other to the daughter strand in DNA replication, the sequence of the “base / structure” complementary to the “base / structure” sequence on the parent strand side A DNA replication process that empirically learns the process of synthesizing daughter-strand DNA using the parent strand as a template by recombining with the daughter strand and restoring the original helical or parallel double-stranded structure. of習方 method.   The DNA model teaching material having a double-stranded structure according to claim 1 or 2, wherein two sets of DNA model teaching materials having the same “base / structure” sequence are used, and the double strands of the two sets of model teaching materials. The DNA / structure is separated into two single-stranded DNA / structures corresponding to the two helical single-stranded DNAs, and the two single-stranded DNA / structures are both parental strands, and the other DNA Model teaching materials are also separated into single-stranded DNA / structures, and these two DNAs / structures are both daughter strands, and “bases / structures” corresponding to the sequences of the “bases / structures” on the parent chain side. And recombination with a daughter strand having a complementary “base / structure” sequence to form two double-stranded structures in which the single-chain combination is different from the original combination, thereby creating the parent chain. Experientially learn the process of synthesizing daughter-strand DNA using as a template Learning method of DNA replication process.   Using the DNA model teaching material according to claim 3, by separating the parallel double-stranded structure from one end of the parallel double-stranded structure into two linear single-stranded backbones / structures corresponding to the leading strand and the lagging strand, A structure corresponding to a replication bubble in DNA replication is formed, and the “linear single-stranded backbone / structure” is continuously bonded to the structure corresponding to the leading strand. Learning of the DNA replication process by experientially learning the process of discontinuous replication performed in the DNA replication bubble by advancing the binding of fragments and structures one by one in the direction opposite to the leading strand Method. In the DNA model teaching material according to claim 5, by using a combination of a magnet and a piece of iron attracted to it, or a combination of a magnet and a magnet for a binding part of a “base pair / structure”, a pair can be combined and separated. Three devices representing the following three processes that take place at the replication fork at the end of the replication bubble where DNA replication takes place:
(1) The process of separating a parallel double-stranded structure into a leading strand and a lagging strand is made by separating the “base pair / structure” into two “bases / structure” by placing the “base pair / structure” on the tip of the block piece, A two-structure separator that simulates the separation process in a replica fork by obtaining two single-chain backbone structures;
(2) The process of continuously synthesizing double strands using the leading strand as a template is separated from the structure corresponding to the leading strand and the single-stranded backbone / structure representing the complementary DNA single strand. Immediately after exiting the outlets of the two channels by passing through the two channels that are close to the outlet, the structure is coupled by the attraction force of the magnet, so that the replication process in the leading strand of the replication fork is performed. A double-stranded replication device using the leading strand to be simulated as a template;
(3) A process in which double strands are divided into Okazaki fragments using a lagging strand as a template and synthesized discontinuously is divided into a single-chain backbone structure corresponding to the lagging strand and a plurality of complementary “Okazaki fragments. Immediately after exiting the outlet of the two channels through the two channels whose entrance is separated and the outlet is approaching, the structure is coupled by the attractive force of the magnet, A DNA model teaching material provided with a replication fork simulator having a double-stranded replication device using a lagging strand as a template for simulating a replication process in a lagging strand in a replication fork.   Using the DNA model teaching material according to claim 7, three processes occurring at the replication fork in DNA replication, that is, (1) separating a parallel double-stranded structure into two DNA single strands, that is, a leading strand and a lagging strand Process, (2) the process of continuous replication of DNA that proceeds in the direction of the replication fork using the leading strand as a template, and (3) the synthesis of multiple Okazaki fragments individually using the lagging strand as a template DNA replication process that empirically learns the process of discontinuous replication of DNA that progresses discontinuously in the opposite direction, but generally in the same direction as the leading strand, ie, in the same direction as the replication fork Learning method.   Claims that can be written on a single DNA model by encrypting an arbitrary message with the sequence of “base pair / structure” using a decryption table created by imitating a genetic decryption table of a living body A method for learning a genetic information code, wherein the encryption of a message is empirically learned by encrypting a message using the DNA model teaching material according to any one of 1, 2, 3, and 7.   An arbitrary message is divided, encrypted with a base sequence using the decryption table, written into a plurality of DNA models according to any one of claims 1, 2, 3, or 7, and linked together Can be used to encrypt and write a long message into a single model, and to empirically encrypt genetic information by dividing and encrypting a long message using it Learning method of genetic code to learn.   8. The DNA model teaching material according to any one of 1, 2, 3, and 7, wherein the backbone / structure is made of a flexible polyurethane rope or tube.

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