CN111850136B

CN111850136B - Application of MRVI1 gene as marker for screening excellent meat quality traits of beef cattle

Info

Publication number: CN111850136B
Application number: CN202010616289.5A
Authority: CN
Inventors: 姜平; 赵志辉; 靳子康
Original assignee: Guangdong Ocean University
Current assignee: Guangdong Ocean University
Priority date: 2020-06-30
Filing date: 2020-06-30
Publication date: 2022-09-20
Anticipated expiration: 2040-06-30
Also published as: CN111850136A

Abstract

The invention discloses application of MRVI1 gene as a marker for screening excellent meat quality traits of beef cattle. The invention discloses 8 SNP sites on MRVI1 gene, which discovers that the polymorphic sites of MRVI1 gene are related to economic traits such as cow fat coverage rate, perirenal fat, eye muscle area and the like by carrying out genotyping and gene frequency analysis and beef quality and carcass trait association analysis on the polymorphic sites of a cow population, and solves the problem of screening important molecular genetic markers related to beef quality and carcass trait at present. And lays a foundation for genetic workers to breed high-quality flocks in early stage, improve meat production performance and improve meat quality.

Description

Application of MRVI1 gene as marker for screening excellent meat quality traits of beef cattle

Technical Field

The invention relates to the technical field of molecular breeding, in particular to application of MRVI1 gene as a marker for screening excellent meat quality traits of beef cattle.

Background

Single Nucleotide Polymorphism (SNP) is taken as the most widely applied third generation genetic marker technology at present, and has important function and application value in the field of animal genetic breeding research. SNPs genotyping technology and method are emerging continuously, and molecular biology technology is promoted to develop dramatically, and the detection method of gene polymorphic sites mainly comprises direct DNA sequencing, restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR), single-strand conformation polymorphism, DNA chip/array analysis and the like. However, for these various methods, the direct DNA sequencing method is the simplest and most accurate for detecting SNPs, and is suitable for the detection of large-population animal samples, providing greater opportunities and challenges for the research of animal individual genetic backgrounds.

The Chinese Simmental cattle is a large-scale milk and meat dual-purpose cattle which is continuously improved and optimized and cultivated after the introduction of China, has unique production performance and good meat properties, and shows huge industrial advantages and development potential. In recent years, research emphasis in the beef cattle field in China has been shifted from growth and development traits to meat quality and carcass traits, and fat coverage is one of important carcass and economic traits and is an important standard for measuring cattle quality traits. Fat coverage is the ratio of the fat coverage area of the surface of the carcass of a beef cattle to the total area of the carcass. Carcass body surface fat coverage rate is one of indexes of carcass grading standards, and the carcass fat coverage rate of super-grade beef cattle is more than 90%; the carcass fat coverage rate of the A-grade beef cattle is 80-90 percent; beef cattle ranked as B-grade cattle with carcass fat coverage less than 80%. When the back of the cow is pressed by fingers to fall on the 6 th to 7 th thoracic rib to the lumbar vertebra part, the force generated by burning can touch the spine, which indicates that the fat layer is very thin and the fat coverage rate is very poor; when the finger is pressed, a great force is needed to touch the spine, which indicates that the fat layer is thick and the fat coverage rate is good. The eye muscle area is the cross section of the muscle between the 12 th to the 13 th ribs and is the cross section of the longest muscle of the back of the livestock, the eye muscle area character has close correlation with the meat production performance of the livestock and has very obvious positive correlation with the weight of the cattle before slaughtering, the weight of the net meat, the slaughtering rate, the net meat rate and the like, so the eye muscle area is an important index for measuring the meat quality in animal breeding and has a particularly important position. Perirenal fat is an important index for measuring cattle slaughter traits, and the accumulation of perirenal fat directly reflects the cattle body content.

Therefore, from the genetic point of view, the genetic marker of the molecule is taken as a main means for researching the quality traits of the beef, and the quality of future cattle herds is improved by improving related meat quality or carcass traits, so that the genetic marker is very necessary, and important gene resources and theoretical basis are provided for breeding new cattle.

The mouse retrovirus integration site 1 homolog (MRVI 1) gene is located on the 15 th chromosome of cattle, and codes 21 exons, wherein the length of the transcript is 6312bp, the open reading frame is 2736bp, and 911 amino acids are included. The protein coded by MRVI1 gene can participate in the conduction of Nitric Oxide (NO) signal, influence the synthesis of cGMP, activate cGMP dependent protein kinase PKG, and regulate the functions of the related cardiovascular system, such as cardiac muscle, vascular smooth muscle and blood platelet, etc. There are related documents reporting that MRVI1 gene can cause blood pressure change of body, mainly sending out signal through cGMP dependent protein kinase type I (cGKI), so as to relax various smooth muscles, and blood flow in blood vessel can be reduced after vascular smooth muscle is relaxed, so as to reduce blood pressure, regulate and control vascular tension and gastrointestinal motility, mainly showing abnormal blood pressure and serious gastrointestinal dysfunction. It has been shown (Shaughanesy JD Jr, Largaesspaada DA, Tian E, et al. Mrvi1, a common MRV integration site in BXH2 myeloid leukamia, encodes a protein with homology to a lymphoid-restricted membrane protein Jaw1. oncogene.1999; 18(12):2069-2084.doi:10.1038/sj. onc.2419) that MRV integration of MRVI1 gene induces myeloid leukemia in mice by altering expression of genes critical to bone marrow cell growth and/or differentiation, and thus the gene may play an important role as a myeloid leukemia tumor suppressor gene.

At present, no molecular marker exists for measuring that MRVI1 gene is obviously related to fat coverage rate, perirenal fat and eye muscle area in meat quality and carcass traits of Chinese Simmental cattle.

Disclosure of Invention

The invention aims to provide application of MRVI1 gene as a marker for screening excellent meat quality traits in beef cattle. The method for detecting meat quality and carcass trait fat coverage rate, perirenal fat and eye muscle area of Chinese Simmental cattle by using the genetic marker of the MRVI1 gene solves the problem of screening the genetic markers of important molecules related to the marker traits such as the cattle fat coverage rate, the perirenal fat and the eye muscle area. Lays a foundation for early breeding of genetic workers and meat quality improvement.

The first purpose of the invention is to provide the application of MRVI1 gene as a marker for screening beef cattle with excellent meat quality traits.

A second object of the present invention is to provide the use of g.41970426A > G, g.41970520T > C, g.41970609A > G, g.41970714A > G, g.41971686G > A or g.41971818G > A for the evaluation of beef cattle fat coverage.

A third object of the present invention is to provide the use of g.41970426A > G, g.41970520T > C, g.41970609A > G, g.41970626G > A, g.41970714A > G, g.41971818G > A or g.41972009A > C for the evaluation of perirenal fat traits in beef cattle.

The fourth purpose of the invention is to provide the application of g.41971686G > A in the evaluation of the beef cattle eye muscle area.

A fifth object of the present invention is to provide the use of g.41970426A > G, g.41970609A > G, g.41970626G > A, g.41970714A > G or g.41971818G > A for the evaluation of beef cattle carcass length.

The sixth purpose of the invention is to provide a method for evaluating the excellent meat quality character of beef cattle.

A seventh object of the present invention is to provide a method for evaluating fat coverage of beef cattle.

An eighth object of the present invention is to provide a method for evaluating the perirenal fat trait of beef cattle.

The ninth purpose of the invention is to provide a method for evaluating the eye muscle area of beef cattle.

The tenth object of the present invention is to provide a method for evaluating the perirenal fat trait of beef cattle.

The above object of the present invention is achieved by the following scheme:

the inventor finds that the MRVI1 gene is related to the screening of excellent meat quality traits of cattle, so the invention claims the application of the MRVI1 gene as a marker for screening the excellent meat quality traits of the cattle.

Further, the invention discovers that 6 polymorphic sites which are obviously related to fat coverage rate are respectively g.41970426A > G, g.41970520T > C, g.41970609A > G, g.41970714A > G, g.41976G > A and g.41168971818G > A on the MRVI1 gene; the total 7 polymorphic sites which are obviously related to perirenal fat are g.41970426A > G, g.41970520T > C, g.41970609A > G, g.41970626G > A, g.41970714A > G, g.41971818G > A and g.41972009A > C sites (P < 0.01); one site was significantly correlated with eye muscle area, being the g.41971686G > A site (P < 0.05); the g.41970426A > G, g.41970609A > G, g.41970626G > A, g.41970714A > G, g.41971818G > A sites are obviously related to carcass length.

Wherein, g.41970426A > G site: the slaughter rate of individuals carrying the AA genotype is obviously higher than that of individuals carrying the GA genotype, the fat coverage rate of individuals carrying the AA genotype is obviously lower than that of individuals carrying the GA genotype, and the perirenal fat weight of individuals carrying the AA genotype is obviously lower than that of individuals carrying the GG genotype (P < 0.05);

g.41970520T > C site: the kidney fat content of individuals carrying the CC genotype is obviously higher than that of individuals carrying the TT genotype (P < 0.05);

g.41970609A > G site: the slaughter rate of the individuals carrying the AA genotype is obviously higher than that of the individuals carrying the GA genotype, the fat coverage rate of the individuals carrying the AA genotype is obviously lower than that of the individuals carrying the GA genotype, and the perirenal fat weight of the individuals carrying the AA genotype is obviously lower than that of the individuals carrying the GG genotype (P < 0.05);

g.41970626G > A site: the slaughtering rate of individuals carrying GG genotype is obviously higher than that of individuals carrying GA genotype, and the kidney fat content and carcass length of individuals carrying GG genotype are obviously lower than those of individuals carrying AA genotype, (P < 0.05);

g.41970714a > G site: the dressing percentage of the individuals carrying the AA genotype is obviously higher than that of the individuals carrying the GA genotype, the kidney fat content of the individuals carrying the AA genotype is obviously lower than that of the individuals carrying the GG genotype, and the fat coverage rate of the individuals carrying the AA genotype is obviously lower than that of the individuals carrying the GA genotype (P < 0.05);

g.41971686G > A site: the fat coverage rate of an individual carrying GG genotype is obviously lower than that of an individual carrying AG genotype, and the eye muscle area of the individual carrying GG genotype is obviously higher than that of an individual carrying AA genotype;

g.41971818g > a site: the fat content of the kidney of an individual carrying GG genotype is obviously lower than that of an individual carrying GA and AA genotypes, the carcass fat coverage rate of the individual carrying GG genotype is obviously lower than that of the individual carrying GA genotype, the carcass length of the individual carrying GG genotype is obviously lower than that of the individual carrying GA and AA genotypes, and the thickness of thigh muscle of the individual carrying GA genotype is obviously higher than that of the individual carrying AA genotype;

g.41972009A > C site: the kidney fat content of an individual carrying the AA genotype is obviously lower than that of an individual carrying the CA genotype, and the waist thickness of the individual carrying the AA genotype is obviously lower than that of an individual carrying the CC genotype.

The invention therefore claims the following:

the application of g.41970426A > G, g.41970520T > C, g.41970609A > G, g.41970714A > G, g.41971686G > A or g.41971818G > A in evaluating the fat coverage rate of beef cattle;

the application of g.41970426A > G, g.41970520T > C, g.41970609A > G, g.41970626G > A, g.41970714A > G, g.41971818G > A or g.41972009A > C in the evaluation of the beef cattle perirenal fat trait;

g.41971686G > A for use in the assessment of beef cattle eye muscle area;

the application of g.41970426A > G, g.41970609A > G, g.41970626G > A, g.41970714A > G or g.41971818G > A in evaluating the carcass length of beef cattle.

The invention also provides protection: a method for evaluating the excellent meat quality of beef cattle detects the genotype of MRVI1 gene.

A method for evaluating the fat coverage rate of beef cattle detects the genotypes of g.41970426A > G, g.41970520T > C, g.41970609A > G, g.41970714A > G, g.41971686G > A or g.41971818G > A.

A method for evaluating the perirenal fat of beef cattle detects the genotypes of g.41970426A > G, g.41970520T > C, g.41970609A > G, g.41970626G > A, g.41970714A > G, g.41971818G > A or g.41972009A > C.

A method for evaluating the eye muscle area of beef cattle features that the genotype of g.41971686G > A is detected.

Compared with the prior art, the invention has the following beneficial effects:

the inventor of the invention discloses the application of a genetic marker which is obviously related to MRVI1 gene, fat coverage rate, perirenal fat and eye muscle area character as a marker auxiliary selection for screening excellent meat quality character of beef cattle, and also applies to the breeding of early beef cattle. The inventor finds 8 SNP loci, discovers that the polymorphic loci of MRVI1 gene are related to economic traits such as beef fat coverage rate, perirenal fat, eye muscle area and the like by carrying out genotyping and gene frequency analysis on the polymorphic loci of a beef colony and correlation analysis on the polymorphic loci and the beef traits, and solves the problem of screening important molecular genetic markers related to the beef traits and the beef traits at present. And lays a foundation for genetic workers to breed high-quality flocks in early stage, improve meat production performance and improve meat quality.

Drawings

FIG. 1 is a diagram of the MRVI1 SNP1(g.41970426A > G) site mutation site sequencing assay.

FIG. 2 is a diagram of the sequencing detection of the mutation site at MRVI1 SNP2(g.41970520T > C).

FIG. 3 is a sequence chart of MRVI1 SNP3(g.41970609A > G) site mutation site.

FIG. 4 is the sequence detection map of the mutation site of MRVI1 SNP4(g.41970626G > A).

FIG. 5 is a sequence detection diagram of the mutation site of MRVI1 SNP5(g.41970714A > G).

FIG. 6 is the MRVI1 SNP6(g.41971686G > A) site mutation site sequencing map.

FIG. 7 is the MRVI1 SNP7(g.41971818G > A) site mutation sequencing map.

FIG. 8 shows the sequence detection map of the mutation site at the SNP8(g.41972009A > C) of MRVI 1.

FIG. 9 shows the SNPs locus chain reaction of MRVI1 gene in beef cattle population.

Detailed Description

The present invention is further described in detail below with reference to specific examples, which are provided for illustration only and are not intended to limit the scope of the present invention. The test methods used in the following examples are all conventional methods unless otherwise specified; the materials, reagents and the like used are, unless otherwise specified, commercially available reagents and materials.

Example 1 amplification of the genome-wide MRVI1 Gene of the Simmental cattle population in China

First, experiment method

1, sample selection

Selecting a certain large cattle farm cattle herd in the inner Mongolia Wula cover area, collecting samples in an intravenous blood collection mode, and collecting 50 samples from different individuals. The whole genome DNA extraction is carried out by adopting a TIANGEN company blood genome DNA extraction kit, and the specific operation is carried out according to the kit instruction. The extracted DNA samples were stored in a-80 ℃ freezer for further use.

2, primer design

MRVI1 gene primers were designed and PCR amplification was performed. Intercepting two sequences MRVI1-A and MRVI1-B of the MRVI1 gene (ENSBTAT00000046140.4) of cattle, wherein the nucleotide sequences of the two sequences are respectively shown as SEQ ID NO: 1 to 2.

The primer design is carried out according to the two fragments, wherein the amplification primers of the amplified fragment MRVI1-A (the nucleotide sequences are respectively shown as SEQ ID NO: 1) are as follows:

MRVI1-A-F：5’-CTTACTGGCTGTGGAACATCA-3’(SEQ ID NO：3)；

MRVI1-A-R：5’-AATCTGGCAACTCTAGTGGTG-3’(SEQ ID NO：4)。

the amplification primers of the amplified fragment MRVI1-B (the nucleotide sequences are respectively shown as SEQ ID NO: 2) are as follows:

designing DNA oligos, wherein the specific primer sequence is as follows:

MRVI1-B-F：5’-CCACCACTAGAGTTGCCAGAT-3’(SEQ ID NO：5)；

MRVI1-B-R：5’-GTCCTTGCTCCTCCACTGAG-3’(SEQ ID NO：6)。

3, amplification of MRVI1 Gene

Firstly, mixing PCR amplification products of every 50 samples, sending the products to Beijing Jinzhizi sequencing, and then analyzing the sequencing result to find out SNP sites. According to the PCR sequencing results of MRVI1-A and MRVI1-B, SNP sites are found. Further 95 samples were subjected to PCR amplification. Sequencing and genotyping.

The specific operation is as follows:

the PCR amplification system is as follows: 2 × Power Taq PCR Master Mix 20.0 μ L; 1.0 μ L of PCR Reverse primer; PCR Forward primer 1.0. mu.L; 3.0. mu.L of DNA (25 mg/L); ddH ₂ O 15μL。

Gene PCR amplification reaction program: 5min at 95 ℃; at 95 ℃ for 30s, 60 ℃ for 30s, and 72 ℃ for 1min, and 35 cycles; 5min at 72 ℃; storing at 16 ℃.

The PCR product was recovered according to the procedure of the DNA recovery kit instructions, and the recovered PCR amplification product was sent to Biotech for sequencing, and was compared and analyzed using DNAStar and Chormas software.

Second, experimental results

For MRVI1 gene, 8 SNPs including g.41970426A > G, g.41970520T > C, g.41970609A > G, g.41970626G > A, g.41970714A > G, g.41971686G > A, g.41971818G > A and g.41972009A > C were detected in the Western Tuer cattle population in China, as shown in FIGS. 1-8. The sequence of the promoter region of the MRVI1 gene (ENSBTAT00000046140.4) was chosen, where g.41970426A > G, g.41970520T > C, g.41970609A > G, g.41970626G > A and g.41970714A > G were located on the segment MRVI1-A, where g.41971686G > A, g.41971818G > A and g.41972009A > C were located on the segment MRVI 1-B.

Example 2

First, experiment method

Genotype frequency refers to the ratio of the number of individuals with a certain genotype for a trait to the total number of individuals in a population. PAA ═ NAA/N, where PAA represents the frequency of AA genotypes at a locus; NAA represents the number of individuals in the population having the AA genotype; and N is the total number of detection groups.

Gene frequency refers to the relative ratio of a certain number of genes in a population to the total number of its alleles. The formula for the calculation can be written as: PA is (2NAA + NAa)/2N. In the formula, PA represents allele A frequency, NAA represents the number of individuals having AA genotype in the population, and NAa represents the number of individuals having AA genotype in the population.

Hardy-Winberg's law (Hardy-Weinberg equibrium), also known as the law of genetic equilibrium, is defined as: in the most ideal case, the genotype frequency of an allele and the frequency of an allele are constant in inheritance, i.e., gene equilibrium is maintained. This situation needs to satisfy the following points: the population is large enough; no mutation occurs; randomly mating individuals in the population; fourthly, no natural selection exists; no new gene is added. The frequencies of each gene and each genotype at this time have the following equations: let a be p, a be q, then p + q be 1, AA + AA be p ^2+2pq + q ^2 be 1. The Hardy-Winberg equilibrium law for a population that is randomly mated and large enough in population, genotype frequencies and gene frequencies will not change without mutation, migration and selection.

Second, experimental results

For MRVI1 gene, 8 SNPs are detected in the Western Men Taer cattle population in China, wherein the site of SNP1(g.41970426A > G, Ensemble rs208249746) has 8 heads of mutation homozygous GG individuals, 42 heads of GA types and 45 heads of wild AA. GG genotype frequency of 0.084, GA genotype frequency of 0.442, AA genotype frequency of 0.474, G allele frequency of 0.305, and T allele frequency of 0.695; the A allele therefore predominates, with wild type AA being the predominant genotype.

SNP2(g.41970520T > C, Ensemble rs210035614) locus, 7 heads for CC type individuals, 42 heads for CT type and 46 heads for wild TT type. The genotype frequency of CC was 0.074, the genotype frequency of CT was 0.442, the genotype frequency of TT was 0.484, the C allele frequency was 0.295, and the T allele frequency was 0.705; the T allele therefore predominates, with wild type TT as the predominant genotype.

SNP3(g.41970609A > G, Ensemble rs211384477), 8 heads for GG type individuals, 42 heads for AG type individuals and 45 heads for AA type individuals. GG genotype frequency of 0.084, AG genotype frequency of 0.442, AA genotype frequency of 0.474, G allele frequency of 0.305, and A allele frequency of 0.695; the A allele therefore predominates, with wild type AA being the predominant genotype.

SNP4(g.41970626G > A, Ensemble rs208898729) site, 46 heads for wild type GG individuals, 41 heads for AG type and 8 heads for AA type. The genotype frequency of GG is 0.0484, the genotype frequency of AG is 0.432, the genotype frequency of AA is 0.084, the allele frequency of G is 0.7 and the allele frequency of A is 0.3; the G allele therefore predominates, with wild type GG being the predominant genotype.

SNP5(g.41970714A > G, Ensemble rs209751199) site, 8 heads of mutation homozygous GG individuals, 42 heads of AG type and 45 heads of wild type AA. GG genotype frequency of 0.084, AG genotype frequency of 0.442, AA genotype frequency of 0.474, G allele frequency of 0.305, and A allele frequency of 0.695; the A allele therefore predominates, with wild type AA being the predominant genotype.

SNP6(g.41971686G > A, Ensemble rs207488012) locus, 64 heads in wild type GG type individuals, 28 heads in GA type and 3 heads in AA. GG genotype frequency of 0.674, GA genotype frequency of 0.295, AA genotype frequency of 0.031, G allele frequency of 0.821, A allele frequency of 0.179; the G allele therefore predominates, with wild type GG being the predominant genotype.

SNP7(g.41971818G > A, Ensemble rs209429084), 51 heads for wild type GG individuals, 37 heads for GA type and 7 heads for AA type. GG genotype frequency of 0.537, GA genotype frequency of 0.389, AA genotype frequency of 0.074, G allele frequency of 0.732, and A allele frequency of 0.268; the G allele therefore predominates, with wild type GG being the predominant genotype.

The SNP8(g.41972009A > C, Ensemble rs110730746) site, the CC individual has 11 heads, the CA type has 46 heads, and the wild type AA type has 38 heads. The genotype frequency of CC was 0.116, that of CA was 0.484, that of AA was 0.400, that of C allele was 0.358 and that of A allele was 0.642; the A allele therefore predominates, with mutant heterozygotic CA as the predominant genotype. The genotype frequencies, allele frequencies and Harden Winberg's law data of the SNP sites of the MRVI1 gene are shown in Table 1.

TABLE 1 genotype frequency, allele frequency and Hardy-Weinberg's law data for SNP sites of MRVI1 genes

Example 3 correlation analysis between 8 SNP sites of MRVI1 gene and meat quality and carcass traits of Simmental cattle

First, experiment method

The meat quality and carcass traits of the Chinese Simmental cattle mainly comprise: hair weight, head weight, carcass weight, slaughter rate, bone weight, hoof weight, skin weight, rumen abomasum, omasum stomach, heart, liver, lung, kidney, perirenal fat, bull's penis, spleen, body chest depth, hind leg circumference, backfat, marbling, eye muscle area, etc. All traits were determined according to the national standard GB/T1723821998.

Second, experimental results

The results show that: the correlation analysis result with the carcass and meat quality traits of Chinese Simmental beef cattle shows that: g.41970426A > G locus has significant correlation with meat quality and carcass traits such as slaughter rate, perirenal fat, carcass fat coverage rate and the like (P < 0.05): the dressing percentage of the individuals carrying the AA genotype is obviously higher than that of the individuals carrying the GA genotype, the fat coverage rate of the individuals carrying the AA genotype is obviously lower than that of the individuals carrying the GA genotype, and the perirenal fat weight of the individuals carrying the AA genotype is obviously lower than that of the individuals carrying the GG genotype (P < 0.05);

g.41970520t > C site has significant correlation with perirenal fat content (P < 0.05): the kidney fat content of the individuals carrying the CC genotype is obviously higher than that of the individuals carrying the TT genotype (P < 0.05);

g.41970609A > G has significant correlation with dressing percentage, perirenal fat, carcass fat coverage (P < 0.05): the dressing percentage of the individuals carrying the AA genotype is obviously higher than that of the individuals carrying the GA genotype, the fat coverage rate of the individuals carrying the AA genotype is obviously lower than that of the individuals carrying the GA genotype, and the perirenal fat weight of the individuals carrying the AA genotype is obviously lower than that of the individuals carrying the GG genotype (P < 0.05);

g.41970626G > A site has significant correlation with dressing percentage, perirenal fat and carcass length (P < 0.05): the slaughtering rate of individuals carrying GG genotype is obviously higher than that of individuals carrying GA genotype, and the kidney fat content and carcass length of individuals carrying GG genotype are obviously lower than those of individuals carrying AA genotype, (P < 0.05);

g.41970714a > G sites were significantly associated with dressing percentage, perirenal fat and carcass fat coverage (P < 0.05): the dressing percentage of the individuals carrying the AA genotype is obviously higher than that of the individuals carrying the GA genotype, the kidney fat content of the individuals carrying the AA genotype is obviously lower than that of the individuals carrying the GG genotype, and the fat coverage rate of the individuals carrying the AA genotype is obviously lower than that of the individuals carrying the GA genotype (P < 0.05);

g.41971686g > a site is significantly associated with carcass fat coverage and eye muscle area (P < 0.05): the fat coverage rate of an individual carrying GG genotype is obviously lower than that of an individual carrying AG genotype, and the eye muscle area of the individual carrying GG genotype is obviously higher than that of an individual carrying AA genotype;

g.41971818g > a site was significantly associated with perirenal fat, carcass fat coverage and carcass length (P < 0.05): the fat content of the kidney of an individual carrying GG genotype is obviously lower than that of an individual carrying GA and AA genotypes, the carcass fat coverage rate of the individual carrying GG genotype is obviously lower than that of the individual carrying GA genotype, the carcass length of the individual carrying GG genotype is obviously lower than that of the individual carrying GA and AA genotypes, and the thickness of thigh muscle of the individual carrying GA genotype is obviously higher than that of the individual carrying AA genotype;

g.41972009A > C site perirenal fat is significantly correlated (P < 0.05): the kidney fat content of an individual carrying the AA genotype is obviously lower than that of an individual carrying the CA genotype, and the waist thickness of the individual carrying the AA genotype is obviously lower than that of an individual carrying the CC genotype.

The specific data are shown in tables 2 and 3.

TABLE 2 correlation of carcass and meat quality traits of Simmental cattle in China with SNPs of MRVI1 gene

Table 2 notes: a, B, C indicate very significant differences (P <0.01), a, B, C indicate significant differences (P < 0.05). DW (carcass weight, Kg), DP (slaughter rate,%), KFW (perirenal fat weight, Kg), GFW (genital fat weight, Kg), MBS (marbling score, score range 1-9), FCS (fat color) score, score range 1-8), BFT (back fat thickness, cm), FCR (fat coverage,%)

TABLE 3 correlation of carcass and meat quality traits of Simmental cattle in China with SNPs of MRVI1 gene

Table 3 notes: a, B, C indicate very significant differences (P <0.01), a, B, C indicate significant differences (P < 0.05). NWB (bone dry weight, Kg), CL (carcass length, cm), CD (carcass depth, cm), CBD (carcass chest depth, cm), TMT (thigh muscle thickness, cm), TL (waist thickness, cm), REA (eye muscle area, cm2), MCS (muscle color score, score range 1-6).

Example 4 linkage reaction between 8 SNP sites of MRVI1 Gene and haplotype analysis

Linkage Disequilibrium (LD), also known as allelic association, is common among several symbols that are used to measure LD, the most important being D' and r ² . When D' and r ² When the value of (A) is zero, the linkage is completely balanced, D' and r ² When the value of (A) is 1, linkage is completely unbalanced and D'<At 1, the value of D' indicates how much linkage disequilibrium is present.

First, experiment method

Based on the above, linkage analysis is carried out on SNPs loci of MRVI1 gene by Haploview software, and a haplotype block (haplotype block) is constructed in a D' value 95% confidence interval.

Second, experimental results

As a result, strong linkage was found between the 8 SNPs sites (D' ═ 1, r2>0.9), and a haplotype domain was constructed between the sites, as shown in FIG. 9. There are mainly 6 haplotypes, H1(0.625), H2(0.151), H3(0.091), H4(0.047), H5(0.042), H6(0.012) and others (0.032), as shown in table 4.

TABLE 4 haplotype frequency of the promoter of the MRVI1 gene

From the continuous SNPs, 6 combinations (combinations with the number of individuals of 3 or more) with research significance were formed, and the correlation between different haplotypes and meat quality and carcass traits was further analyzed. As a result, it was found that: the related haplotypes have significant correlations with carcass weight (DW), slaughter rate (DP), perirenal fat weight (KFW), reproductive organ fat weight (GFW), carcass Fat Coverage (FCR), Carcass Length (CL), carcass chest depth (CBD), and Muscle Color Score (MCS), as shown in Table 5. Haplotypes H1H1 and H1H2 are associated with Dressing Percentage (DP) (< 0.05); haplotypes H1H2, H1H4, H1H5, and H2H3 are associated with reproductive organ fat (P < 0.05); H1H1 and H1H2 were significantly associated with fat coverage (P < 0.05). In addition, H1H1, H1H3, H1H5, and HH2H3 were significantly associated with carcass length. In addition, H1H2 was significantly correlated with carcass chest depth (CBD) and Muscle Color Score (MCS), and H1H4 and H2H3 were also significantly correlated with Muscle Color Score (MCS), with the results shown in table 5.

TABLE 5 correlation analysis results of haplotype combination (number of individuals is not less than 3) and cattle carcass and meat quality traits

Table 5 notes: a, B, C indicate very significant differences (P <0.01), a, B, C indicate significant differences (P < 0.05). DW (carcass weight, Kg), DP (slaughter rate,%), KFW (perirenal fat weight, Kg), GFW (reproductive fat weight, Kg), MBS (marbling score, score range 1-9), FCS (fat color score, score range 1-8), BFT (back fat thickness, cm), FCR (carcass fat coverage,%), NWB (bone net weight, Kg), CL (carcass length, cm), CD (carcass depth, cm), CBD (carcass chest depth, cm), TMT (thigh muscle thickness, cm), TL (waist thickness, cm), REA (eye muscle area, cm2), MCS (muscle color score, score range 1-6).

In conclusion, the method for detecting carcass and meat quality character fat coverage rate, perirenal fat and eye muscle area in the Simmental cattle population in China by using the genetic marker of the MRVI1 gene has the advantages that the genetic marker of the MRVI1 gene is used as a marker-assisted selection application for screening excellent meat quality characters of beef cattle, the problem of screening important molecular genetic markers related to carcass and meat quality characters of cattle at present is solved, and a foundation is laid for early breeding of high-quality cattle by genetic workers to improve meat production performance and meat quality. MRVI1 gene g.41970426A > G, g.41970520T > C, g.41970609A > G, g.41970714A > G, g.41971686G > A and g.41971818G > A sites can be used as molecular markers of fat coverage rate in carcass traits; the g.41970426A > G, g.41970520T > C, g.41970609A > G, g.41970626G > A, g.41970714A > G, g.41971818G > A and g.41972009A > C sites can be used as molecular markers of perirenal fat in the slaughter trait; the g.41971686G > A locus can be used as a genetic marker of the eye muscle area in the meat quality character, and different haplotype combinations are obviously related to the beef carcass and meat quality character, so that the gene has higher application value, is applied to the future molecular breeding of cattle, and provides gene resources and theoretical basis for the selection of beef cattle fat character and the cultivation of new varieties.

It should be finally noted that the above examples are only intended to illustrate the technical solutions of the present invention, and not to limit the scope of the present invention, and that other variations and modifications based on the above description and thought may be made by those skilled in the art, and that all embodiments need not be exhaustive. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Sequence listing

<110> Guangdong ocean university

Application of <120> MRVI1 gene as marker for screening excellent meat quality traits in beef cattle

<160> 6

<170> SIPOSequenceListing 1.0

<210> 1

<211> 969

<212> DNA

<213> cattle (bos)

<400> 1

cttactggct gtggaacatc acacaggtct ttttgcccct ttaaacctta ttagtttcct 60

tttcaaaaga atggtataat agctctattt cacggggcac ataggaaggt acatgctttt 120

atggagagtg tctaatatag tgattagaat atcgtagatg ttcaatataa ggtttatata 180

acacatacag acacatagac acacagacat acactcacac ctccttcctc acatgcacac 240

aaactgaagt ttctagttgt ctttgcagga attgctgcta gattcataaa atcaactttt 300

ggagtaccat tccctaaaat ggggtttttg gaccaactgc ataagtgaga atcacccgag 360

ggccttaaat aaaatatagg tttctgggcc tcactttaga gccacaagat tagaatttct 420

agaaaagggg tccagagagt ttcacacttg atgattctat tgcacaatga agttggagaa 480

acagcagtaa agagtttggt aattcattct aatccctcta cttgcagttc tagtagctat 540

cacgttgtgg ttttgccagt gggagcctgt tcccagtcga tggataggtg taggtgcctg 600

agggaaagca tggctagtac ccatgagtct tctctggttc catctacaga aatagttatt 660

tatgggtttg acagacagca tgtagtatag tctcatcagg aatctctttc gtaacaagca 720

aggagaagag acagtccagg actggatgtc cgtggaaggg gctgggatag aagcacagtg 780

ggctaggttt gggggagaaa gcctgccaca gccaggaact gaggataagg actgtatgca 840

gccaggcagc tgtcaccagg agggcttgag gccacacgtc tcgaggcacc gacacctaga 900

gccctcagca tgactggcga acactttctg aggtggtaag tgatggccca ccactagagt 960

tgccagatt 969

<210> 2

<211> 966

<212> DNA

<213> cattle (bos)

<400> 2

ccaccactag agttgccaga tttagcaaat aaaaatacag gatgagccat taaatttcat 60

taaattagaa tttcagattt tatatatata tatatatacg tacatacaca catatatggg 120

gcttccctgg taggtcagct ggtaaagaat tcacctgcaa tgcaggagat gccagtttga 180

ttcctgagtt gggaaaatct cctgaagaag gaataggcta cccactccag tattcttggg 240

cttctggggt ggcttagatg gtaaagaatc cgcccgcaat gcggcagacc tgggtttgat 300

ccctgggttg ggcagatgcc ctggaagagg gcatggcaac ccactccagt attcttgcct 360

ggagaatccc catggacaga ggaaccttgt gggttacagt ccatggagtc acaaagagtc 420

agatactact gagcaattaa gcacacagca cagcatatat atgtgtgtgt gtgtatgtaa 480

gcatgtcctg tgcaatattt gggacatact tatactaaaa tagatatgtg ttatctgaaa 540

ttcaagtcta agtaggtgtc ctgcattcta tctggcagtc ctacatagga tttctctgag 600

ctgcctctaa ctgctgaaaa gggttggaga ccccatgtga ctggccaggg cccacagcac 660

catgatcttt ctctgggtgg ggggctgcac ccaaggtggt gaggagcgag taagggcaag 720

gtgtggactt caggagagag cagctcttcc tcacctgtgt ctgagcaggg gcaggaaact 780

cactggtatt gataagcaag tctgagatgc tagcactctg ctaagccttt cagtatcatc 840

tcatcaaatc ctcctgcaac cctaggagtt aggcattgtg atcccagtga ttcccacttt 900

agagatgagg agactgaggc tccacgaggt taagaccaca gggctactca gtggaggagc 960

aaggac 966

<210> 3

<211> 21

<212> DNA

<213> cattle (bos)

<400> 3

cttactggct gtggaacatc a 21

<210> 4

<211> 21

<212> DNA

<213> cattle (bos)

<400> 4

aatctggcaa ctctagtggt g 21

<210> 5

<211> 21

<212> DNA

<213> cattle (bos)

<400> 5

ccaccactag agttgccaga t 21

<210> 6

<211> 20

<212> DNA

<213> cattle (bos)

<400> 6

gtccttgctc ctccactgag 20

Claims

1. The application of reagents for detecting genotypes of g.41970426A > G, g.41970520T > C, g.41970609A > G, g.41970714A > G, g.41971686G > A and g.41971818G > A in evaluating fat coverage of Simmental cattle in China is characterized in that g.41970426A > G, i.e., Ensemble rs208249746, g.41970520T > C, i.e., Ensemble rs210035614, g.41970609A > G, i.e., Ensemble rs 384477, g.41970714A > G, i.e., Ensemble rs 209759, g.41168976G > A, i.e., Ensemble rs207488012, and g.411818G > A, i.e., Ensemble rs 429084.

2. Use of reagents for detecting genotypes for g.41970426A > G, g.41970520T > C, g.41970609A > G, g.41970626G > A, g.41970714A > G, g.41971818G > A and g.41972009A > C for assessing the perirenal fat trait of Taer cattle in China, characterized in that g.41970426A > G, Ensemble rs208249746, g.41970520T > C, Ensemble rs210035614, g.41970609A > G, Ensemble rs 382114477, g.41970714A > G, Ensemble rs 752091199, g.41971818G > A, Ensemble rs 429084, g.4197g > G A, Ensemble rs 2082082082082082082082084597231, and g.4197001109.

3. The application of the reagent for detecting the genotype of g.41971686G > A in evaluating the eye muscle area of the Chinese Simmental cattle is characterized in that the g.41971686G > A is Ensemble rs 207488012.

4. Use of reagents for detecting the genotypes of g.41970426A > G, g.41970609A > G, g.41970626G > A, g.41970714A > G and g.41971818G > A for the assessment of carcass length in Chinese Simmental cattle, characterised in that g.41970426A > G, Ensemble rs208249746, g.41979A > G, Ensemble rs211384477, g.41970714A > G, Ensemble rs209751199, g.41978G > A, Ensemble rs209429084, and g.41976062G > A, Ensemble rs 208898729.

5. A method for evaluating fat coverage rate of Chinese Simmental cattle is characterized in that genotypes of g.41970426A > G, g.41970520T > C, g.41970609A > G, g.41970714A > G, g.41971686G > A and g.41971818G > A are detected, and the fat coverage rate of Chinese Simmental cattle is evaluated according to the genotypes, wherein g.41970426A > G, i.e. Ensemble rs208249746, g.41970520T > C, i.e. Ensemble rs210035614, g.41970609A > G, i.e. Ensemble rs211384477, g.41970714A > G, i.e. Ensemble rs 2091191199, and g.41976G > A, i.e.e. Ensemble rs 484848488012, and g.41971818G > A, i.e.e. Ensemble 42422091682092099.

6. A method for evaluating the character of the kidney-girth fat of Chinese Western Men Taer cattle is characterized in that the genotypes of g.41970426A > G, g.41970520T > C, g.41970609A > G, g.41970626G > A, g.41970714A > G, g.41971818G > A and g.41972009A > C are detected, and the character of the kidney-girth fat of Chinese Western Men Taer cattle is evaluated according to the genotypes of the G.41970426262626262626262626G, i.e. Ensemble rs 2089724970T > C, i.e. Ensemble 210035614, g.41970609A, i.e. Ensemble 211384477, g.97414A > G, i.e. Ensemble rs 209119759, g.411818G, i.e. Ensemble rs 412099746, and 75 g.419748A, i.g.412099748, 411818G, i.e. Ensemble rs 412099, and 1109A, wherein the character of the genotype of the No. Ensemble 9748A, i.412099748A, i.412099, g.e.

7. A method for evaluating the eye muscle area of Chinese Simmental cattle is characterized in that the genotype of g.41971686G & gt A is detected, and the eye muscle area of Chinese Simmental cattle is evaluated according to the genotype, wherein g.41971686G & gt A is Ensembles 207488012.

8. A method for evaluating trunk elongation of Chinese Simmental cattle is characterized in that genotypes of g.41970426A > G, g.41970609A > G, g.41970626G > A, g.41970714A > G and g.41971818G > A are detected, trunk elongation of Chinese Simmental cattle is evaluated according to the genotypes of the g.41970426A > G, namely Ensemble rs208249746, g.41970609A > G, namely Ensemble rs 21138444477, g.41970714A > G, namely Ensemble rs209751199, g.41978G > A, namely Ensemble rs209429084 and g.410626G > A, namely Ensemble 208898729.