RU2316207C2 - Selection-genetic method for obtaining high-performance and persistent lymphocytosis-resistant cattle stock - Google Patents

Abstract

FIELD: zootechny, veterinary science.

SUBSTANCE: it is necessary to establish the genotypes of cows and breeding bulls in breeding stock according to BoLA DRB3 gene. Animals should be divided into groups by different sensitivity to persistent lymphocytosis: with genotype including two alleles referring to sensitivity (S/S); with genotype including two alleles referring to resistance (R/R), with genotype including one allele referring to sensitivity and another one - to resistance (S/R), with genotype including two neutral alleles (N/N), with genotype including one allele referring to sensitivity and another being neutral (S/N), with genotype including one allele referring to resistance and another being neutral (R/N). For reproduction it is necessary to match parental couples as follows: one parent with genotype R/R, another - S/S; or one parent with genotype S/R, and another S/S; or one parent with genotype N/R, and another - S/R; or one parent with genotype N/S, and another R/R. The innovation enables to increase resistance to persistent lymphocytosis in cattle along with the increase of cattle performance.

EFFECT: higher efficiency.

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Description

The invention relates to livestock and veterinary medicine and is intended for use in the formation of a highly productive herd of cattle resistant to persistent lymphocytosis.

According to statistics, among the infectious diseases of cattle, the proportion of leukemia is 53.7%. In 2004, 3215 leukemic dysfunctional sites were registered in the territory of 60 federal subjects.

Animals in which persistent lymphocytosis or the tumor stage of leukemia has been identified, according to the current legislation (Order No. 359 of the Ministry of Agriculture of the Russian Federation of May 11, 1999) are subject to immediate destruction.

The closest to the essence of the proposed is a method for the genetic prevention of leukemia in cattle (RU 2032996, А01К 67/02) - a prototype that includes testing cows for the presence of erythrocyte antigens of blood groups, establishing cows resistant to leukemia, with additional genealogical analysis along the lines; testing pedigree bulls for the same erythrocyte antigens, with selection of resistant bulls (according to offspring) and subsequent crossbreeding of resistant parents to obtain stable offspring (4).

The known method has several disadvantages:

- among animals with persistent lymphocytosis, there are carriers of blood groups, defined as providing resistance to this disease (relative relationship of genotype and resistance);

- the selection of resistant animals does not take into account the relationship of factors blood group / productivity

M.J.T. Van Eijk, J. A. Stewart-Haynes, J. E. Bever (1992); G.E.Sulimova, I.G. Udina, G.O. Shaikhayev, I.A. Zakharov (1995); M. Zanotti et al. (1996); S.P. Pavlenko (2000); I.G. Udina et al. (2000) showed that if the animal genotype contains alleles (one or two) of the BoLA DRB 3 gene associated with resistance to persistent lymphocytosis, then this animal does not develop this stage of leukemia.

It was also found that the susceptibility of the animal, as a rule, is associated with its increased productivity and is associated with alleles of the BoLA DRB 3 gene, which increase the risk of persistent lymphocytosis.

The identification of alleles of the BoLA DRB 3 gene (5) consists in the amplification of exon 2 of the BoLA DRB 3 gene (the size of the PCR product is 284 bp), analysis of the restriction polymorphism of this region using endonucleases Rsa I, Hae III, Bst Y I. DNA mapping - Patterns obtained using the above restriction enzymes allow the identification of more than 100 alleles of the BoLA DRB 3 gene. The presence of BoLA DRB alleles 3.2 * 11, * 28, * 23 (U-alleles) in the genotype ensures the resistance of animals to persistent lymphocytosis, and BoLA alleles DRB 3.2 * 16, * 24, * 22, * 8 (H - alleles) associated with increased susceptibility to this disease is often found in highly productive animals. Neutral alleles (H - alleles) are not associated with either productivity or resistance.

The objective of the invention is to increase the resistance of cattle populations to persistent lymphocytosis with a simultaneous increase in their productivity.

The solution to the problem is achieved by the fact that in the breeding and genetic method of creating a highly productive and resistant to persistent lymphocytosis of a herd of cattle, DNA testing of the brood stock and bulls by the BoLA DRB3 gene is performed, then the animals are divided into groups with different sensitivity to persistent lymphocytosis: with the genotype , including two alleles, causing sensitivity (H / H); with the genotype, including two alleles that cause resistance (U / Y); with the genotype, including one allele, which determines the sensitivity, and the other resistance (U / H); with a genotype comprising two neutral alleles (N / H); with a genotype that includes one allele, which determines sensitivity, and the other neutral (B / N); with a genotype that includes one allele that causes resistance and the other neutral (Y / H) and for reproduction, the parental pairs are selected so as to ensure maximum saturation of the population with U / H genotypes in the offspring.

In this case, the U - allele in the genotype performs the function of protecting against persistent lymphocytosis, and the H - allele is a marker of high productivity.

The method is as follows.

Sperm samples are taken from breeding bulls for DNA analysis. The exon 2 of the BoLA DRB 3 gene is amplified (the size of the PCR product is 284 bp), and then the restriction polymorphism of this region is analyzed using endonucleases Rsa I, Nae III, Bst Y I. The animal genotype is determined by the BoLA DRB 3 gene. A bullfile is created , in which, in addition to the main zootechnical characteristics, the genotype of the BoLA DRB 3 gene is taken into account.

Blood samples are taken from breeding cows for DNA analysis. Exon 2 of the BoLA DRB 3 gene is amplified (the size of the PCR product is 284 bp), and then restriction polymorphism of this region is analyzed using endonucleases Rsa I, Nae III, Bst Y I. The animal genotype is determined by the BoLA DRB 3 gene.

Then the animals are divided into groups: with the genotype, including two alleles, causing sensitivity to persistent lymphocytosis (H / H); with the genotype, including two alleles, causing resistance to persistent lymphocytosis (U / U); with a genotype that includes one allele, which determines sensitivity, and another resistance to persistent lymphocytosis (U / H); with a genotype that includes two alleles that are neutral with respect to persistent lymphocytosis (N / H); with a genotype that includes one allele, which determines sensitivity, and the other neutral (B / N); with a genotype that includes one allele that causes resistance and the other neutral (Y / H) and for reproduction, the parental pairs are selected so as to ensure maximum saturation of the population with U / H genotypes in the offspring.

As a result of our studies, we found that in production bulls (n = 60) used by the breeding enterprise 000 NSPE “Aster” in Krasnodar, the genotypes are distributed as follows (Table 1).

Table 1 The frequency of occurrence of genotypes for the BoLA DRB 3 gene in manufacturing bulls used in the artificial insemination system of the Krasnodar Territory Genotype Frequency (%) U / U 3 U / N 7 W / h fourteen H / h 28 H / n 33 N / A fifteen

Thus, created a file of existing bulls. The analysis of table 1 allows us to conclude that the need for directional selection to obtain bulls with the genotype UU or purchase such bulls.

In the Privolnoye farm of the Kanevsky district of the Krasnodar Territory (n = 90), we established the following distribution of genotypes for the BoLA DRB 3 gene (Table 2).

table 2 Frequency of genotypes of the BoLA DRB 3 gene in the Privolnoye farm Genotype Frequency (%) H / h 60 B / w 10 H / n thirty

For maximum saturation of the population with U / H genotypes, it is necessary to select parental pairs as follows (Table 3):

Table 3 Possible selection of parental pairs and distribution of genotypes in the offspring Mother Father Possible distribution of genotypes in the offspring H / h U / U 100% U / H B / w U / U 50% B / W + 50% B / W H / n U / U 50% B / W + 50% N / A

Then in the second generation you can get 80% of animals with the genotype U / H; 5% Y / Y; 15% Y / N

In other farms, a different distribution of genotypes and, therefore, a different selection of parental pairs is possible (Table 4):

Table 4 Possible selection and distribution of genotypes in the offspring Parent Parent Possible distribution of genotypes in the offspring H / h U / U 100% U / H B / w U / U 50% B / W + 50% B / W H / n U / U 50% B / W + 50% N / A U / N B / w 25% B&W + 25% Y / L + 25% H / N + 25% Y / N N / A B / w 50% H / N + 50% Y / N

Table 5 presents the distribution of genotypes (n = 50) in the Beisug farm of the Primorsko-Akhtarsky district and productivity indicators for each of the genotypes, which confirms the reliability of the proposed method. From table 5 it follows that the group of animals with the genotype H / W significantly exceeds the productive indicators of the group U / U, H / U and H / N.

Table 5 The relationship of productive indicators and genotype for the gene BoLA DRB 3 Genotype U / A ** WELL** B / W ** H / h H / H * N / A milk yield fat milk yield fat milk yield fat milk yield fat milk yield fat milk yield fat 5730 3.72 5885 3.8 6169 3.8 5867 3.7 5789 3.8 5916 3.77 ** - (P <0.01); * - (P <0.05)

In another farm - OJSC "Druzhba" of the Primorsko-Akhtarsky district, similar results were obtained (table 6).

Table 6 The distribution of genotypes for BoLA DRB 3 in the farm "Friendship" Primorsko-Akhtarsky district (n = 60) Genotype no BoLA DRB 3 N / A WELL U / U H / h B / w LF Productivity, kg 6108 6087 5547 6105 * 7248 5960 * * - (P <0.05)

Information sources

1. Pavlenko S.P. Changes in the expression of BoLA system antigens in different age groups of healthy and sick cattle leukemia // Sat .: Actual issues of diagnosis, prevention and control of leukemia agricultural. animals and birds / Ekaterinburg. - 2000. - P.86-94.

2. Sulimova G.E., Udina I.G., Shaykhaev G.O., Zakharov I.A. DNA polymorphism of the Bola-DRB 3 gene in cattle due to resistance and susceptibility to leukemia // Genetics. - 1995. - No. 9. - S. 1294-1299.

3. Udina I.G. et al. Use of DNA technologies for assessing hereditary resistance to leukemia disease // Thes. doc. II international scientific Conf .: Biotechnology in animal husbandry and veterinary medicine. - M., 2000 .-- S.219-220.

4. Ernst L.K., Shishkov V.P., Petukhov V.P. A method for selecting bulls for resistance to leukemia // RF Patent A 01 K 67/02. -1990.

5. Groenen M.A.M. et al. The nucleotide sequence of bovine MHC class II DQB and DRB genes // Immunogenetics. - 1990, - No. 31. - P.37.

6. Van Eijk M.J.T., Stewart-Haynes J.A., Lewin H.A. Extensive polymorphism of the BoLA DRB3 gene distinguished PCR-RFLP // Anim. Genet. - 1992. - 23. - 483.

7. Xu A., Van Eijk V.J. T., Park Ch. Polymorphism in BoLA - DRB3 Exon 2 correlates with resistance to persistent lymphocytosis caused by bovine leukemia virus // J. of Immunology. - 1993. - V.151. - No. 12. - R. 6977-6985.

8. Zanotti M. et al. Association of BoLA class II haplotypes with subclinical progression of bovine leukaemia virus infection in Holstein - Friesian cattle // Anim. Genet. - 1996. - 27. - P.337-341.

Claims (1)

A method of creating a highly productive and resistant to persistent lymphocytosis of a herd of cattle, which consists in conducting DNA testing of the brood stock and bulls according to the BoLA DRB3 gene, then the animals are divided into groups with different sensitivity to persistent lymphocytosis: with a genotype that includes two alleles causing sensitivity (H / H); with the genotype, including two alleles that cause resistance (U / Y); with a genotype that includes one allele that determines sensitivity, and the other - resistance (U / H); with a genotype comprising two neutral alleles (N / H); with a genotype that includes one allele, which determines sensitivity, and the other, neutral (B / N); with a genotype that includes one allele that causes resistance and the other neutral (Y / H) and, in order to ensure maximum saturation of the population with U / H genotypes in the offspring, parental pairs are selected for reproduction as follows: one parent with the Y / U genotype, and another - B / H; or one parent with the genotype B / W, and the other - B / H; or one parent with the N / A genotype, and the other - B / W; or one parent with the N / H genotype, and the other with U / U.