BROWN SWISS CATTLE ARE DAIRY EFFICIENCY AND HETEROGENEITY IN EAB, EAF LOCI OF BLOOD GROUPS

The article presents the results of study the dairy efficiency of Brown Swiss cattle in the Smolensk region depending on the homozygous and heterozygous state of marker genes EAB and EAF loci of blood groups. The research was carried out using standard immunogenetic and statistical methods with the use of proprietary reagents. It was found that with an increase in the dairy efficiency heifer in the population, the relative number of animals homozygous in the EAB locus decreases, and their lack is revealed. Heterozygous animals were superior to homozygous animals in milk yield for 305 days of first lactation. A group of cows homozygous for the BG3O1T1Y2E`3F`2G allele had increased dairy efficiency and homozygous for the recessive EAB locus allele had decreased dairy efficiency. Animals that were heterozygous for the F / V-locus of blood groups, in terms of milk yield for 305 days of first lactation (4849 kg), duration of productive use (over 13 lactations), and the amount of milk received during the entire productive life of a cow (26 452 -75 792 kg), were superior to analogues that were homozygous for this locus.

Comparative population genomics unveils candidate genes for athletic performance in Hanoverians

Equine athletes have a genetic heritage that has been evolved for millions of years, which provides an opportunity to study the genetics of locomotion pattern and performance in mammals. The Hanoverian, a breed originating in Germany, is arguably among the most athletic of horse breeds, as well as possessing a balanced character and beautiful appearance. Here, we compared the whole genomes of Hanoverian with three other horse breeds (Akhal-Teke, Franches-Montagnes, and Standardbred), using the fixation index (Fst) and cross-population composite likelihood ratio (XP-CLR) methods for testing the multi-locus allele frequency differentiation between populations. We identified 299 and 485 positively selected genes using the Fst and XP-CLR methods, respectively. Further functional analyses showed that the ACTA1 gene is potentially involved in athletic performance in the Hanoverian breed, consistent with its role observed in human population. In addition, three other loci on chromosomes 1 and 20 were identified to be potentially involved in equine physical performance. The selected candidate genes identified in this study may be useful in current breeding efforts to develop improved breeds in regard to athletic performance.

THE POLYMORPHISM OF FIVE MICROSATELLITE DNA LOCI IN THE STUDY OF GRAY UKRAINIAN AND BULGARIAN GREY CATTLE BREEDS

The problem of preserving genetic diversity as a component of the environment, has recently become global. Among the cattle breeds that require special attention in terms of preserving genetic diversity is grey steppe cattle. Grey steppe cattle are very ancient livestock, representatives of grey steppe cattle in Ukraine is Ukrainian Grey, in Bulgaria – Bulgarian Grey breed. The purpose of this study was to conduct a comparative analysis of allele diversity of Ukrainian Grey and Bulgarian Grey cattle breeds using microsatellite DNA loci. This analysis was performed on 32 animals of Ukrainian Grey breed bred in the LLC "Holosiyevo", Brovary district, Kyiv region. Their genetic studies were carried out in the Laboratory of Molecular Genetics and Cytogenetics of Animals in the center of biotechnology and molecular diagnostics of the All-Russian Research Institute of Animal Husbandry (Dubrovitsy vil., Moscow reg.). Genomic DNA was isolated from the biological material obtained from the earmark, according to the method described by N. A. Zinovieva and co-authors. Genetic analysis of Ukrainian Grey and Bulgarian Grey breeds was conducted at five microsatellite DNA loci: BM1824, BM2113, ETH225, SPS115, TGLA126, which are included in the list recommended by the ISAG-FAO for genotyping of cattle. The data on Bulgarian Grey breed were used after Teneva A. et.al. (2005). Electrophoretic separation of DNA fragments by capillary electrophoresis was performed on the device MegaBace 500. For identification of alleles of studied loci MS Genetic Profiler 2.0 software was used. These alleles of each animal were summed to a Microsoft Excel spreadsheet. The resulting matrix of genotypes served as the basis for the statistical processing of the results. For statistical data processing software Cervus 3.0.3, PowerStatsV12 (Promega), GENALEX 6 was used. The studies carried out in 5 microsatellite DNA loci identified 26 alleles in Ukrainian Grey breed and 30 alleles in Bulgarian Grey breed. The SPS115 locus in both breeds identified 7 alleles, with the highest frequency of allele 248 bp. At Ukrainian Grey breed in BM2113 locus the highest frequency was discovered at the alleles 135 and 139 bp, while in micropopulation of Bulgarian Grey breed the highest frequency was demonstrated by the allele 133 bp. In BM1824 locus allele 188 bp has the highest frequency. Alleles 188 and 192 are present only in the micropopulation of Ukrainian Grey breed. In the micropopulation of Bulgarian Grey breed allele 184 is identified with frequency of occurrence 0.386. In ETH225 locus in the micropopulations of Ukrainian Grey and Bulgarian Grey breeds 6 loci were revealed. Allele 152 was present only in the group of Ukrainian Grey breed, and allele 158 with frequency 0.043 and allele 146 with frequency 0.129 were identified only in the micropopulation of Bulgarian Grey breed. The highest frequency of alleles in the studied Bulgarian Grey breed was at allele 140 with frequency 0.371, and in the micropopulation of Ukrainian Grey breed it was at allele 148. In TGLA126 locus 7 alleles were identified: 109, 115, 117, 119, 121, 123, 125. Allele 115 was detected only in the micropopulation of Ukrainian Grey breed, and allele 109 with frequency 0.014 and allele 121 with frequency 0.014 were detected only in the micropopulation of Bulgarian Grey breed. Furthermore, the quantity of the informative value of the used markers (PIC) was calculated. The larger the value for the PIC locus is, the more informative the locus is as a marker. According to Botstein et al. the locus with PIC > 0.500 value is very informative (high polymorphic); with 0.5 > PIC > 0.25 is informative enough (moderately polymorphic); and with PIC < 0.250 is slightly informative. In the micropopulation of Ukrainian Grey breed the highest value was observed at loci BM1824 PIC = 0.710, and ETH225 PIC = 0.710. In the micropopulation of Bulgarian Grey breed most polymorphic loci were BM2113 PIC = 0.790 and ETH225 PIC = 0.740. The average value of Na at Ukrainian Grey breed was 5.2 alleles in five loci; in the micropopulation of Bulgarian Grey breed the average value of Na was 6.0 alleles; the average value of the observed degree of heterozygosity Ho in micropopulations of Ukrainian Grey breed was 0.656, at Bulgarian Grey breed it was 0.783. The expected degree of heterozygosity He at Ukrainian Grey breed was 0.704, at Bulgarian Grey breed it was 0.813, that indicates a greater genetic diversity in the micropopulation of Bulgarian Grey breed. The total average value of Fis in the micropopulation of Ukrainian Grey breed was 0.074, at Bulgarian Grey breed it was 0.030. The excess of heterozygotes was detected in the micropopulation of Ukrainian Grey breed on loci BM2113 and BM1824 (18.2 and 2.5%, respectively), in the micropopulation of Bulgarian Grey breed it was detected on BM1824 locus (15.1%). Heterozygosity deficit was identified on all the loci, with the exception of the loci BM2113 (-0.182) and BM1824 (-0.025) in the micropopulations of Ukrainian Grey breed and BM1824 locus (-0,151) in Bulgarian Grey breed. The highest value Fis was found in SPS115 locus (0,444) of Ukrainian Grey breed. Precisely this can explain the high deficit of heterozygosity in the micropopulation of Ukrainian Grey breed. This study confirms the effectiveness of the use of microsatellite DNA loci to characterize the genetic diversity of populations of grey steppe cattle bred in many countries around the world. Ukrainian Grey and Bulgarian Grey breeds are genetically very similar to each other. The genetic analysis shows that they have a low genetic variability, although in both micropopulations deficit of heterozygotes was detected, but it was higher in micropopulation of Ukrainian Grey breed. The results may be useful in breeding grey cattle breeds, to monitor them in order to preserve their genetic diversity.

The House Fly Y Chromosome is Young and Minimally Differentiated from its Ancient X Chromosome Partner

Canonical ancient sex chromosome pairs consist of a gene rich X (or Z) chromosome and a male- (or female-) limited Y (or W) chromosome that is gene poor. In contrast to highly differentiated sex chromosomes, nascent sex chromosome pairs are homomorphic or very similar in sequence content. Nascent sex chromosomes arise frequently over the course of evolution, as evidenced by differences in sex chromosomes between closely related species and sex chromosome polymorphisms within species. Sex chromosome turnover typically occurs when an existing sex chromosome becomes fused to an autosome or an autosome acquires a new sex-determining locus/allele. Previously documented sex chromosome transitions involve changes to both members of the sex chromosome pair (X and Y, or Z and W). The House fly has sex chromosomes that resemble the ancestral fly karyotype that originated 100 million years ago, and therefore house fly is expected to have X and Y chromosomes with different gene content. We tested this hypothesis using whole genome sequencing and transcriptomic data, and we discovered little evidence for genetic differentiation between the X and Y in house fly. We propose that house fly has retained the ancient X chromosome, but the ancestral Y was replaced by an X chromosome carrying a male determining gene. Our proposed hypothesis provides a mechanisms for how one member of a sex chromosome pair can experience evolutionary turnover while the other member remains unaffected.