The intensification of dairy cattle farming, accompanied by a decline in reproductive functions, requires the implementation of modern genetic selection methods. One promising direction is marker-assisted selection (MAS) using candidate genes associated with reproductive traits. The progesterone receptor gene (PGR), which plays a key role in regulating ovulation, embryo implantation, and pregnancy maintenance, is considered as such a candidate. The aim of this study was to analyze the T81637C (rs41614030) polymorphism of the PGR gene in the cattle population of the Republic of Tatarstan. The study was conducted on two cattle groups: 297 Holstein cows and 67 sires. Genotyping was performed using the PCR-RFLP method with restriction by EcoRV endonuclease. It was found that the cow population is characterized by a significant deviation from the Hardy-Weinberg equilibrium (χ² = 8.52; p < 0.05) with an excess of heterozygotes (CT = 57.3%) and an increased frequency of the C allele (0.572). In contrast, the bull population was in a state of genetic equilibrium (χ² = 0.38) with a distribution of alleles (C = 0.493; T = 0.507) and genotypes (CT = 53.7%; CC = 22.4%; TT = 23.9%). The obtained fixation index values (Fis = -0.169 for cows and -0.075 for bulls) indicate effective breeding work without inbreeding depression. The polymorphism informativeness (PIC = 0.370- 0.375) characterizes the marker as moderately informative. A comparative analysis with data from other studies confirmed the universal nature of the genotype distribution according to the CT > CC > TT scheme in various Holstein cattle populations. The results demonstrate the prospects of using the T81637C polymorphism of the PGR gene in genomic selection programs to improve the reproductive qualities of dairy cattle.
The aim of this study was to assess the population-genetic structure and parameters of genetic biodiversity at the polymorphic locus g.4491A>G (A375G) of the GHRL gene in cattle of the Tatarstan type of the Kholmogor breed. Ghrelin, encoded by the GHRL gene, plays a key role in regulating appetite, energy metabolism, growth, and dairy productivity, making it a promising marker for breeding. Blood samples from 91 cows served as the material for DNA testing. Genotyping was performed using PCRRFLP with the BstKT I restriction endonuclease. As a result, three genotypes were identified: AA (9.9%), GA (52.7%), and GG (37.4%). The frequency of allele A was 0.363, and that of allele G was 0.637. Population-genetic analysis showed that the studied population is in a state of HardyWeinberg equilibrium, with a predominance of heterozygous genotypes observed, and the polymorphism information content (PIC) characterizes the locus as moderately polymorphic and informative for breeding programs. A comparative analysis with literature data revealed significant interbreed and geographical variability in the frequencies of the GHRL gene. The obtained results emphasize the importance of considering the genetic specificity of local breeds and confirm the potential of using GHRL gene polymorphism as a molecular-genetic marker to enhance the efficiency of cattle breeding. The study was carried out within the framework of the state assignment, registration number 125031003428-9.
Molecular genetic markers, such as the polymorphism of the kappa-casein gene (CSN3), are a important tool for increasing the efficiency of dairy cattle breeding. The aim of this study was to investigate CSN3 polymorphism in a Holstein cattle population and to assess its associations with blood biochemical parameters reflecting the animals’ metabolic status. In the studied herd (146 animals), allele (A — 0,651, B — 0,349) and genotype frequencies were determined using the PCR-RFLP method: AB (47,9 %; 70 animals), AA (41,1 %; 60 animals), and BB (11,0 %; 16 animals). The results of the biochemical analysis for 12 blood serum parameters were statistically processed using t-test Student in the context of the identified genotypes. Significant associations of CSN3 polymorphism with the biochemical profile were revealed. Carriers of the B allele, especially those with the BB genotype, were characterized by a significantly higher level of protein metabolism indicators (total protein, albumin, urea, creatinine) and activity of enzymes from the classes of aminotransferases (AST, ALT) and hydrolases (alkaline phosphatase), as well as lower concentrations of bilirubin and glucose compared to animals with the AA genotype. The obtained data indicate more intensive metabolism and efficient liver function in cows with the B allele. The results confirm the pleiotropic effect of the CSN3 gene, linking the genetic variant not only to milk quality but also to the body’s metabolic profile. This substantiates the feasibility of using this gene as a marker for the comprehensive assessment and prediction of metabolic adaptation in Holstein cattle breeding programs. The work was carried out according to a state assignment, registration number 125031003428-9
The article presents the results of a study on the combined genotypes of OPN (c.8514C/T) and IGF-1 (512T/C) genes in a population of Holstein heifers (n=202). The experiment was conducted at the Lenin Breeding Farm (Atninsky District, Republic of Tatarstan), and laboratory analyses were carried out at the Tatar Research Institute of Agriculture, Kazan Scientific Center of the Russian Academy of Sciences. The relevance of the study is driven by the need to identify genetic markers associated with reproductive traits in cattle, as fertility indicators alongside milk productivity determine the economic efficiency of dairy farming. The OPN and IGF-1 genes are involved in the regulation of embryogenesis, implantation, folliculogenesis, and early embryonic development; however, their combined interaction remains insufficiently studied. Genotyping was performed using PCR-RFLP with restriction endonucleases BseI (for OPN ) and BstSNI (for IGF-1 ). The analysis revealed the presence of all nine possible combined genotype combinations, confirming the genetic heterogeneity of the studied population. The highest frequency was observed for the combined genotype CT/AB (29.7%), while the lowest frequencies were found for CC/BB (2.0%) and CC/AA (3.0%) by OPN / IGF-1 . A pattern of decreasing frequency of combined genotypes was established with an increasing number of homozygous loci. Comparison of the observed and theoretically expected distributions showed no statistically significant deviations (χ² = 4.67; p > 0.05), indicating independent allele combination of the studied genes and the absence of factors disrupting genetic equilibrium in the sample. The obtained data can be applied in breeding programs for marker-assisted selection of parental pairs, genetic passportization, and monitoring of the genetic structure of cattle populations.
Pink snow mold, caused by the low-temperature ascomycete Microdochium.nivale (Fr.) Samuels and I.C. Hallett), is a regular occurrence in winter triticale (x Triticosecale, Wittm.). It is the most common and damaging phytopathogen in temperate and cold climates. Field experiments were conducted at the laboratory of winter rye and triticale breeding of the Tatar Scientific Research Institute of Agriculture FRC KazSC of RAS in 2020–2022. The experiments were carried out under both natural and artificial infectious conditions. The samples were screened in the laboratory by infecting detached leaves with the most virulent strain of Microdochium.nivale , F00608. The study focused on 50 hexaploid samples of winter triticale from the N.I. Vavilov VIGRR gene collection. The results demonstrated that the mean disease damage score for winter triticale samples on the artificial infection background was 6.39 ± 1.52, while in natural conditions of infection development, the score was 3.34 ± 0.94. A correlation coefficient of r = -0.708 was observed between snow mold damage on the artificial infectious background and yield. The development of snow mold resulted in a significant loss in yield, amounting to 50.4%. The results of the field studies demonstrated that the majority of winter triticale cultivars were susceptible to pink snow mold. The forms with relatively high levels of field and laboratory resistance were identified. The sources of field resistance to snow mold have been identified as potential candidates for further use in breeding. The varieties Beta 2, Doctrine 110, Capral, Nemchinovsky 56, Bashkirskaya korotkostebelnaya, Tsekad 90 and Altaysky 5 have been identified as resistant to both natural infection and epiphytotic load. The varieties Pyatrus, Kroha, Privada, Gorka, Almaz, Capella, Tribun have demonstrated high resistance to pink snow mold in detached leaves, and are therefore recommended for use in genetic studies.
