Argali (Ovis ammon), the largest species among all wild sheep, is native to mountainous regions of Central and East Asia, spreading mainly throughout such countries as Tajikistan, Kyrgyzstan, Kazakhstan, Afghanistan, Mongolia, Russia and China. Intraspecific taxonomy of argali remains unclear, and currently, most researchers recognize up to nine subspecies. The aim of our work was to investigate the phylogenetic relationship between populations of O. ammon based on genome-wide SNP analysis. Five subspecies, Altai (O. a. ammon) (n = 6), Gobi (O. a. darwini) (n = 5), Pamir (O. a. polii) (n = 12), Tian Shan (O.a. karelini) (n = 15) and Kyzylkum (O. a. severtzovi) (n = 4), were genotyped using Illumina OvineHD BeadChip. In addition, complete mitogenome sequences from 30 of those samples were obtained. After quality control procedures, 65,158 SNPs were selected for the subsequent analyses. Neighbor-Net dendrogram and principal component analysis (PCA) revealed that the five subspecies could be grouped into four clusters. It was shown that a population from Altai formed a cluster with Gobi subspecies. The highest pairwise F_ST genetic distance was between O. a. ammon and O. a. severtzovi (0.421) and the lowest were between O. a. polii and O.a. karelini (0.083) and between O. a. ammon and O. a. darwini (0.040) subspecies. Genetic diversity was higher in Central Asian argali as compared to East Asian populations. O. a. severtzovi had an admixed origin and consisted of two genetic components—73.5 ± 0.2% of O. a. polli and 26.5 ± 0.2% of urial (O. vignei). TreeMix analysis revealed a migration event from urial to O. a. severtzovi argali. The analysis of complete mitogenomes supported the results based on whole-genome genotyping. Considering that all the mtDNA sequences of O. a severtzovi belonged to O. ammon and not to O. vignei, we concluded that gene flow in this group was associated with urial males. As this is only the first work on intraspecific taxonomy and genetic diversity of argali based on genome-wide SNP genotyping and the analysis of complete mitogenomes, we suggest that more genetic studies are needed to clarify the status of Gobi and Tian Shan argali.

The search for SNPs and candidate genes that determine the manifestation of major selected traits is one crucial objective for genomic selection aimed at increasing poultry production efficiency. Here, we report a genome-wide association study (GWAS) for traits characterizing meat performance in the domestic quail. A total of 146 males from an F₂ reference population resulting from crossing a fast (Japanese) and a slow (Texas White) growing breed were examined. Using the genotyping-by-sequencing technique, genomic data were obtained for 115,743 SNPs (92,618 SNPs after quality control) that were employed in this GWAS. The results identified significant SNPs associated with the following traits at 8 weeks of age: body weight (nine SNPs), daily body weight gain (eight SNPs), dressed weight (33 SNPs), and weights of breast (18 SNPs), thigh (eight SNPs), and drumstick (three SNPs). Also, 12 SNPs and five candidate genes (GNAL, DNAJC6, LEPR, SPAG9, and SLC27A4) shared associations with three or more traits. These findings are consistent with the understanding of the genetic complexity of body weight-related traits in quail. The identified SNPs and genes can be used in effective quail breeding as molecular genetic markers for growth and meat characteristics for the purpose of genetic improvement.

Traces of long-term artificial selection can be detected in genomes of domesticated birds via whole-genome screening using single-nucleotide polymorphism (SNP) markers. This study thus examined putative genomic regions under selection that are relevant to the development history, divergence and phylogeny among Japanese quails of various breeds and utility types. We sampled 99 birds from eight breeds (11% of the global gene pool) of egg (Japanese, English White, English Black, Tuxedo and Manchurian Golden), meat (Texas White and Pharaoh) and dual-purpose (Estonian) types. The genotyping-by-sequencing analysis was performed for the first time in domestic quails, providing 62,935 SNPs. Using principal component analysis, Neighbor-Net and Admixture algorithms, the studied breeds were characterized according to their genomic architecture, ancestry and direction of selective breeding. Japanese and Pharaoh breeds had the smallest number and length of homozygous segments indicating a lower selective pressure. Tuxedo and Texas White breeds showed the highest values of these indicators and genomic inbreeding suggesting a greater homozygosity. We revealed evidence for the integration of genomic and performance data, and our findings are applicable for elucidating the history of creation and genomic variability in quail breeds that, in turn, will be useful for future breeding improvement strategies.

Breeding improvements and quantitative trait genetics are essential to the advancement of broiler production. The impact of artificial selection on genomic architecture and the genetic markers sought remains a key area of research. Here, we used whole-genome resequencing data to analyze the genomic architecture, diversity, and selective sweeps in Cornish White (CRW) and Plymouth Rock White (PRW) transboundary breeds selected for meat production and, comparatively, in an aboriginal Russian breed of Ushanka (USH). Reads were aligned to the reference genome bGalGal1.mat.broiler.GRCg7b and filtered to remove PCR duplicates and low-quality reads using BWA-MEM2 and bcftools software; 12,563,892 SNPs were produced for subsequent analyses. Compared to CRW and PRW, USH had a lower diversity and a higher genetic distinctiveness. Selective sweep regions and corresponding candidate genes were examined based on ZF_ST, hapFLK, and ROH assessment procedures. Twenty-seven prioritized chicken genes and the functional projection from human homologs suggest their importance for selection signals in the studied breeds. These genes have a functional relationship with such trait categories as body weight, muscles, fat metabolism and deposition, reproduction, etc., mainly aligned with the QTLs in the sweep regions. This information is pivotal for further executing genomic selection to enhance phenotypic traits.

In this study, we present the first complete mitochondrial genomes of two species of the genus Ovis – snow sheep (Ovis nivicola) and thinhorn sheep (Ovis dalli). The mitochondrial genomes have a total length of 16,471 and 16,464 bp, respectively, including 13 protein-coding genes (PCGs), 22 tRNA genes, 2 rRNA genes, and a non-coding region. Phylogenetic analyses using nucleotide sequences of the 13 PCGs indicated that O. nivicola and O. dalli clustered with another representative of the Pachyceros subgenus – O. canadensis, which was consistent with the previous morphological classification.

Currently, the intraspecific taxonomy of snow sheep (Ovis nivicola) is controversial and needs to be specified using DNA molecular genetic markers. In our previous work using whole-genome single nucleotide polymorphism (SNP) analysis, we found that the population inhabiting Kharaulakh Ridge was genetically different from the other populations of Yakut subspecies to which it was usually referred. Here, our study was aimed at the clarification of taxonomic status of Kharaulakh snow sheep using mitochondrial cytochrome b gene. A total of 87 specimens from five different geographic locations of Yakut snow sheep as well as 20 specimens of other recognized subspecies were included in this study. We identified 19 haplotypes, two of which belonged to the population from Kharaulakh Ridge. Median-joining network and Bayesian tree analyses revealed that Kharaulakh population clustered separately from all the other Yakut snow sheep. The divergence time between Kharaulakh population and Yakut snow sheep was estimated as 0.48 ± 0.19 MYA. Thus, the study of the mtDNA cytb sequences confirmed the results of genome-wide SNP analysis. Taking into account the high degree of divergence of Kharaulakh snow sheep from other groups, identified by both nuclear and mitochondrial DNA markers, we propose to classify the Kharaulakh population as a separate subspecies.