Prolactin plays an important regulatory function in mammary gland development, milk secretion, and expression of milk protein genes. Hence the PRL gene is a potential genetic marker of production traits in dairy cattle. The gene was mapped on chromosome 23 by Hallerman et al. (1988). It consists of 5 exons and four introns (Camper et al. 1984) encoding the 199-amino-acid mature protein (Wallis 1974). On the basis of sequence analysis of four different cDNA clones, seven possible nucleotide substitutions were described by Sasavage et al. (1982). One of them, recognized by RsaI endonuclease, has become a popular genetic marker used for genetic characterization of cattle populations by means of PCR-RFLP (Mitra et al., 1995). Two allelic variants (B and b) have been distinguished at the DNA level, based on RsaI polymorphism in the third exon of the coding region. It has been suggested that prolactin alleles correlate with milk yield (Lewin et al., 1992).

В статье приведены результаты исследования высшей селекционной группы холмогорской породы по генам молочных белков и гормонов и их взаимосвязь с молочной продуктивностью. У коров холмогорской породы (п=150), принадлежащих ведущим племенным хозяйствам Архангельской области были определены генотипы генов CSN3, LGB, PRL, GH, LEP и их комплексы с использованием метода ПЦР-ПДРФ. В высшей селекционной группе животных из 243 теоретически возможных выявлено наличие 49 комплексных генотипов CSN3/LGB/PRL/GH/LEP, с различной частотой встречаемости. Третья часть животных (33,3%) представлена наиболее часто встречающимися генотипами CSN3АА/LGBАВ/PRLGG/GHLL/LEPAA (16%), CSN3АА/LGBBВ/PRLGG/GHLL/LEPAA (12%) и CSN3АА/LGBBВ/PRLAG/GHLL/LEPAA (5,3%). Наиболее распространенные у холмогорских коров генотипы CSN3AA/LGBAB/PRLGG/GHLL/LEPAA (n=24) и CSN3AA/LGBВB/PRLGG/GHLL/LEP AA (n=18) различаются между собой только по одной позиции — наличию одного или 2-х аллелей В гена бета-лактоглобулина. Оценка молочной продуктивности с учетом комплексных генотипов одновременно по 5 генам показала, что достоверно самый высокий удой 11332 кг молока по сравнению с другими генотипами и средним значением по стаду (Р<0,05) достигнут в группе животных с генотипом CSN3АА/LGBАA/PRLAG/GHLL/LEPAA, не имеющих в составе комплексного генотипа В аллеля молочных белков. Коровы с генотипом CSN3АА/LGBАА/PRLАG/GHLL/LEPAA имеют достоверное преимущество по удою на 1785 кг молока (P<0,05) над животными, имеющими в составе комплексного генотипа 2 аллеля В гена LGB — CSN3АА/LGBBВ/PRLАG/GHLL/LEPAA, и на 1051 кг над коровами с комплексным генотипом CSN3АВ/LGBАВ/PRLАG/GHLL/LEPAA. Лучшей по содержанию жира (4,38%) является группа коров с генотипом CSN3АА/LGBВВ/PRLAG/GHLL/LEPAA, по содержанию белка (3,29%) — с генотипом CSN3АА/LGBВВ/PRLGG/GHLL/LEPAA.The article presents the results of the study of the highest breeding group of Kholmogory breed on the genes of milk proteins and hormones and their relationship with milk productivity. The genotypes of genes CSN3, LGB, PRL, GH, LEP and their complexes were determined in cows of Kholmogory breed (n=150) belonging to the leading breeding farms of the Arkhangelsk region using the PCR-RFLP method. 49 complex genotypes CSN3/LGB/PRL/GH/LEP with different frequency of occurrence were revealed in the highest selection group of animals out of 243 theoretically possible. The third part of the animals (33,3%) are the three most common genotypes CSN3АА/LGBАВ/PRLGG/GHLL/LEPAA (16%), CSN3АА/LGBBВ/PRLGG/GHLL/LEPAA (12%) and CSN3АА/LGBBВ/PRLAG/GHLL/LEPAA (5.3 %). The most common in Kholmogory cows genotypes CSN3AA/LGBAB/PRLGG/GHLL/LEPAA (n=24) and CSN3AA/LGBВB/PRLGG/GHLL/LEPAA (n=18) differ only in one position — the presence of one or 2 alleles B in the gene of beta-lactoglobulin. Evaluation of milk productivity taking into account the complex genotypes simultaneously for 5 genes showed that the highest yield of 11332 kg of milk compared to other genotypes and the average value of the herd (P<0.05) was achieved in the group of animals with the genotype CSN3АА/LGBАA/PRLAG/GHLL/LEPAA, which do not have allele B of milk proteins in the complex genotype. Animals with genotype CSN3АА/LGBАА/PRLАG/GHLL/LEPAA have a significant preference for the yield of milk in 1785 kg of milk (P<0.05) on animals with 2 allele B of  the gene LGB in the complex genotype CSN3АА/LGBBВ/PRLАG/

No abstract

A b s t r a c tReindeer (Rangifer tarandus), the only member of the genus Rangifer, is one of the most interesting object to investigate genetic diversity. One of the technique of studying the genetic structure of populations and parentage identification is to create panels of STR (short tandem repeats) markers. The aim of the current study was the development of multiplex panel of STR markers and assessment of its application to assign the parents and to study biodiversity of Russian reindeer populations. As a biological material for research we used tissue samples (part of ear's lobes) of reindeer of Even (EVN, n = 44), Evenk (EVK, n = 44), Nenets (n = 45) breeds and Tyva population (TUV, n = 35). DNA extraction was performed using Nexttec columns (Germany) according to the manufacturer's instructions. Polymorphism of nine STR markers (NVHRT76, RT9, NVHRT24, RT30, RT1, RT6, RT27, NVHRT21 and RT7) was determined by own procedures using ABI 3130xl DNA analyzer («Applied Biosystems», USA). Statistical analysis was performed in MS Excel 2007 with the plugin GenAIEx v. 6.5, software MSA 4.05, PHYLIP, v. 3.5c, Treev32 and Structure, v. 2.3.4. The studied populations of reindeer were characterized by relatively high levels of genetic diversity. The average number of alleles per locus was 6.11±0.56 in TUV, 6.67±0.50 in NEN, 8.00±0.76 in EVN and 8.89±0.65 in EVK. The smallest effective number of alleles per locus was detected in TUV (3.37±0.47), the maximal value was in EVK (4.89±0.46 alleles per locus), and EVN and NEN occupied an intermediate position (4.42±0.53 and 3.90±0.38, respectively). The number of alleles in single loci ranged from four in NVHRT21 and NVHRT24 for TUV to twelve in RT7 for EVK and RT1 for EVN. The probability of matching genotypes (PI) for the nine loci ranged from 1.84½10 -9 in NEN to 5.9½10 -11 in EVK, showing the high power of the proposed marker panel for parentage identification. The calculation of the mean values of similarity coefficient Q in the i th cluster with the most probable number of clusters such as k = 3 and k = 4 (Q i/k ) revealed high heterogeneity of genetic structure of studied populations. The highest degree of genetic differentiation was shown for TUV (Q 2/3 = 0.899±0.034, Q 3/4 = 0.883±0.035) and for NEN (Q 3/3 = 0.885±0.031, Q 4/4 = 0.813±0.038). The EVN and EVK population were close to each other, and a clear clustering between them was not observed. An estimation of R st (AMOVA) showed that 11.4 % of the total molecular variability was caused by differences between populations, and 88.6 % was due to individual differences between animals (p < 0.01). Evaluation of degree of genetic differentiation of studied populations, using as criteria the values of Nei' genetic distances and pairwise comparisons of F st showed similar trends. TUV population was the most distinct comparing to other populations (D Nei = 0,283-0,502, F st = 0,299-0,452), while it was the most differ from NEN and the closest to EVN. The minimal genetic differences were observed between EVN and EVK (D N...

No abstract