Assessment of the variability of reproductive abilities of a black and white cattle using genealogical data and paratypical factors.

The purpose of this study was to assess the role of paratypical and genetic factors in the variation of the complex of traits associated with the reproductive quality of livestock in the conditions of the CJSC breed livestock factory farm "Irmen" in a retrospective aspect. Black-and-White Irmenskiy interbreeds type breed was officially registered in 2000 by the Ministry of Agriculture of the Russian Federation as a breeding achievement and is a unique cattle subpopulation, bred only at the Irmen breed livestock factory farm, in Western Siberia, (Russia). This type is the best in all of Western Siberia in terms of milk yield and appearance among annual competitions and official state assessments. Therefore, the authors chose this breed as a material of research. Over 19 years, the authors studied the variability of traits such as milk yield, fat and protein content in milk, productive life, insemination rate, calving interval, open days, dry period, calving ease, and body weight. These traits are closely associated with the reproductive characteristics of the Black-and-White breed of the Irmensky subpopulation. The authors assessed the variability of these traits, which is influenced by the factors by "Year", "Lactation number" and "Sire's genotype". The data obtained showed a close genotype-environment interaction. Also, the conditions of feeding and keeping at the breed livestock factory farm have a significant impact on these traits.

Selective constraints in cold-region wild boars may defuse the effects of small effective population size on molecular evolution of mitogenomes.

Spatial range expansion during population colonization is characterized by demographic events that may have significant effects on the efficiency of natural selection. Population genetics suggests that genetic drift brought by small effective population size (Ne) may undermine the efficiency of selection, leading to a faster accumulation of nonsynonymous mutations. However, it is still unknown whether this effect might be balanced or even reversed by strong selective constraints. Here, we used wild boars and local domestic pigs from tropical (Vietnam) and subarctic region (Siberia) as animal model to evaluate the effects of functional constraints and genetic drift on shaping molecular evolution. The likelihood-ratio test revealed that Siberian clade evolved significantly different from Vietnamese clades. Different datasets consistently showed that Siberian wild boars had lower Ka/Ks ratios than Vietnamese samples. The potential role of positive selection for branches with higher Ka/Ks was evaluated using branch-site model comparison. No signal of positive selection was found for the higher Ka/Ks in Vietnamese clades, suggesting the interclade difference was mainly due to the reduction in Ka/Ks for Siberian samples. This conclusion was further confirmed by the result from a larger sample size, among which wild boars from northern Asia (subarctic and nearby region) had lower Ka/Ks than those from southern Asia (temperate and tropical region). The lower Ka/Ks might be due to either stronger functional constraints, which prevent nonsynonymous mutations from accumulating in subarctic wild boars, or larger Ne in Siberian wild boars, which can boost the efficacy of purifying selection to remove functional mutations. The latter possibility was further ruled out by the Bayesian skyline plot analysis, which revealed that historical Ne of Siberian wild boars was smaller than that of Vietnamese wild boars. Altogether, these results suggest stronger functional constraints acting on mitogenomes of subarctic wild boars, which may provide new insights into their local adaptation of cold resistance.