Identification of homozygosity-rich regions in the Holstein genome.

In this study, 371 Holstein cows from six herds and 26 Holstein bulls, which were used in these herds, were genotyped by the Illumina BovineSNP50 array. For runs of homozygosity (ROH) identification, consecutive and sliding runs were performed by the detectRUNS and Plink software. The missing calls did not significantly affect the ROH data.

Assessing the effects of rare alleles and linkage disequilibrium on estimates of genetic diversity in the chicken populations.

Phenotypic diversity in poultry has been mainly driven by artificial selection and genetic drift. These led to the adaptation to the environment and the development of specific phenotypic traits of chickens in response to their economic use. This study evaluated genetic diversity within and between Russian breeds and populations using Illumina Chicken 60K SNP iSelect BeadChip by analysing genetic differences between populations with Hudson's fixation index (F statistic) and heterozygosity.

Assessing the power of principal components and wright's fixation index analyzes applied to reveal the genome-wide genetic differences between herds of Holstein cows.

Background: Due to the advent of SNP array technology, a genome-wide analysis of genetic differences between populations and breeds has become possible at a previously unattainable level. The Wright's fixation index (F) and the principal component analysis (PCA) are widely used methods in animal genetics studies. In paper we compared the power of these methods, their complementing each other and which of them is the most powerful.

[Genome-Wide Analysis of Across Herd F(st) Heterogeneity in Holsteinized Livestock].

To form a reference population necessary for genomic selection of dairy cattle, it is important to acquire information on the genetic diversity of the original population. Our report is the first among the studies on breeding of farm animals to implement Wright's F-statistics for this purpose. Genotyping of animals was performed using BovineSNP50 chip.

[Genomic selection of milk cattle. The practical application over five years].

Genomic selection is a method based on the use of single nucleotide polymorphisms (SNPs) as markers for detecting animal or plant genotype values. The review describes the genomic selection of milk cattle 5 years after the design of dense SNP chips. References to the application of genomic selection to other animal and plant species are given.

[Association of a single nucleotide substitution in intergenic region of chromosome 4 with traits of egg quality in domestic chickens].

The association of SNP2-1 with egg quality traits in domestic chickens was analyzed. SNP2-1 alleles were significantly associated with the thickness of eggshells in chickens of the UK-72 line. The substitution of the SNP2-1 allele Tfor the C allele had an effect of 35 +/- 15 microm, which corresponds to one standard deviation.

[Study of the association between alleles of the growth hormone receptor and prolactin receptor genes of bulls and the milk productivity of their daughters].

A substitution of thyrosine for phenylalanine (F297Y) in the transmembrane domain of the growth hormone receptor (GHR) was tested for significance for breeding evaluation of bulls of the holstenized Black-and-White breed. The breeding value was estimated by the method of daughter yield deviation to contemporaries with modification. The frequency of genotype FF in the bulls examined was 0.

[Association of the DGAT1 gene polymorphism in stud bulls with milk productivity in cows].

The substitution of lysine for alanine (K232A) in the acyl-CoA-diacylglycerol acyltransferase, which is encoded by the DGAT1 gene, was tested for the significance for breeding evaluation of stud bulls of the holsteinized Black-and-White breed. The breeding value (deviation of milk productivity in daughters compared with cows of the same age) was estimated by the DYDC (daughter yield deviation to contemporary) method with modification. The frequency of allele 232K in the bulls examined was 0.

[SNP assisted total genomic selection as a possible accelerator of traditional selection].

Selection using single nucleotide polymorphism (SNP) markers scattered throughout the genome or genomic selection (GS) is considered. This approach permits simultaneous selection of most quantitative trait loci (QTLs) determining the selected trait. According to expert assessment, GS makes it possible to save 92% of the funds spent on traditional selection and is twice as efficient as the latter.

[Analysis of chromosomal localization of loci controlling milk production traits in cattle].

Analysis of the pattern of the chromosomal localization of quantitative trait loci (QTLs) is necessary for comprehensively understanding their functions. The chromosomal localization of QTLs controlling milk production traits has been studied in cattle chromosomes. The distribution of QTLs between chromosomes has proved to be binomial.

[Genetic mapping of loci responsible for milk quality parameters in dairy cattle].

The review presents a definition of loci controlling quantitative traits (quantitative trait loci, QTLs) and localization of all currently known QTLs responsible for milk production traits in dairy cattle. The QTL number and chromosome localization are verified, with special reference to chromosomes 1, 3, 6, 14, 20, and 23. In a number of cases, close location of QTLs for mastitis and for milk production traits was found.

[The detection of the location in cattle chromosomes of a gene presumably determining testis development].

The localization of the putative testis determining gene (TDF) was established with isotopic and nonisotopic methods of in situ hybridization in prometaphasic chromosomes of cattle. The results of both the methods were seen to coincide. The sites of hybridization have been revealed in X-chromosome (R-bands, q2.

[The heterochromatin regions of the mitotic chromosomes in cattle].

Cytochemical and molecular peculiarities of heterochromatic regions of bovine chromosomes have been studied, using specific fluorochrome staining induced decondensation, in situ hybridization, pretreatment of restriction enzymes. The heterochromatin of autosomes demonstrated a strong homogeneity. In chromosome Y two small specific heterochromatic regions were found lacking a long repeated tandem block of nucleotides enriched in GC base pairs and having no tandem block of Bkm repeats (10(4) b.

[Aggregation of heterochromatin regions of chromosomes in Drosophila melanogaster neuroblasts].

Interaction of heterochromatic regions was studied during interphase and mitosis. The interphasic heterochromatin unites, producing 1-8 H-chromocentres. A lack of synapsis between heterochromatic regions in prophase is shown to be a result of hypotonic treatment.

[Staining of interphase and metaphase chromosomes with Procion Yellow 4RS].

A method for staining proteins by procion yellow 4RS on preparates of metaphase and interphase chromosomes is suggested. It is shown that the dye is not bound to either native or denatured DNA in solution.

[Preparation of polytene chromosomes from isolated cell nuclei of the salivary glands of Drosophila].

A method is proposed for preparation of polytene chromosomes free of cytoplasmic substance. The nuclei are isolated using triton X-100 and squashed in 60% propionic acid solution.