Assessing Genomic Diversity and Selective Pressures in Bohai Black Cattle Using Whole-Genome Sequencing Data.

Bohai Black cattle are one of the well-known cattle breeds with black coat color in China, which are cultivated for beef. However, no study has conducted a comprehensive analysis of genomic diversity and selective pressures in Bohai Black cattle. Here, we performed a comprehensive analysis of genomic variation in 10 Bohai Black cattle (five newly sequenced and five published) and the published whole-genome sequencing (WGS) data of 50 cattle representing five "core" cattle populations. The population structure analysis revealed that Bohai Black cattle harbored the ancestry with European taurine, Northeast Asian taurine, and Chinese indicine. The Bohai Black cattle demonstrated relatively high genomic diversity from the other cattle breeds, as indicated by the nucleotide diversity (pi), the expected heterozygosity (H) and the observed heterozygosity (H), the linkage disequilibrium (LD) decay, and runs of homozygosity (ROH). We identified 65 genes containing more than five non-synonymous SNPs (nsSNPs), and an enrichment analysis revealed the "ECM-receptor interaction" pathways associated with meat quality in Bohai Black cattle. Five methods (CLR, θπ, F, θπ ratio, and XP-EHH) were used to find several pathways and genes carried selection signatures in Bohai Black cattle, including black coat color (), muscle development (, , , , and ), fat deposition (, , , and ), reproduction traits (, , and ), and immune system response (, , , and ). Taken together, our results provide a valuable resource for characterizing the uniqueness of Bohai Black cattle.

Ma X ，Cheng H ，Liu Y ，Sun L ，Chen N ，Jiang F ，You W ，Yang Z ，Zhang B ，Song E ，Lei C ... -  《Animals》

Assessing genomic diversity and signatures of selection in Jiaxian Red cattle using whole-genome sequencing data.

Native cattle breeds are an important source of genetic variation because they might carry alleles that enable them to adapt to local environment and tough feeding conditions. Jiaxian Red, a Chinese native cattle breed, is reported to have originated from crossbreeding between taurine and indicine cattle; their history as a draft and meat animal dates back at least 30 years. Using whole-genome sequencing (WGS) data of 30 animals from the core breeding farm, we investigated the genetic diversity, population structure and genomic regions under selection of Jiaxian Red cattle. Furthermore, we used 131 published genomes of world-wide cattle to characterize the genomic variation of Jiaxian Red cattle. The population structure analysis revealed that Jiaxian Red cattle harboured the ancestry with East Asian taurine (0.493), Chinese indicine (0.379), European taurine (0.095) and Indian indicine (0.033). Three methods (nucleotide diversity, linkage disequilibrium decay and runs of homozygosity) implied the relatively high genomic diversity in Jiaxian Red cattle. We used θπ, CLR, F and XP-EHH methods to look for the candidate signatures of positive selection in Jiaxian Red cattle. A total number of 171 (θπ and CLR) and 17 (F and XP-EHH) shared genes were identified using different detection strategies. Functional annotation analysis revealed that these genes are potentially responsible for growth and feed efficiency (CCSER1), meat quality traits (ROCK2, PPP1R12A, CYB5R4, EYA3, PHACTR1), fertility (RFX4, SRD5A2) and immune system response (SLAMF1, CD84 and SLAMF6). We provide a comprehensive overview of sequence variations in Jiaxian Red cattle genomes. Selection signatures were detected in genomic regions that are possibly related to economically important traits in Jiaxian Red cattle. We observed a high level of genomic diversity and low inbreeding in Jiaxian Red cattle. These results provide a basis for further resource protection and breeding improvement of this breed.

Xia X ，Zhang S ，Zhang H ，Zhang Z ，Chen N ，Li Z ，Sun H ，Liu X ，Lyu S ，Wang X ，Li Z ，Yang P ，Xu J ，Ding X ，Shi Q ，Wang E ，Ru B ，Xu Z ，Lei C ，Chen H ，Huang Y ... -  《BMC GENOMICS》

Assessing genomic diversity and selective pressures in Bashan cattle by whole-genome sequencing data.

Specific ecological environments and domestication have continuously influenced the physiological characteristics of Chinese indigenous cattle. Among them, Bashan cattle belongs to one of the indigenous breeds. However, the genomic diversity of Bashan cattle is still unknown. Published whole-genome sequencing (WGS) data of 13 Bashan cattle and 48 worldwide cattle were used to investigate the genetic composition and selection characteristics of Bashan cattle. The population structure analysis revealed that Bashan cattle harbored ancestries with East Asian taurine and Chinese indicine. Genetic diversity analysis implied the relatively high genomic diversity in Bashan cattle. Through the identification of containing >5 nsSNPs or frameshift mutations genes in Bashan cattle, a large number of pathways related to sensory perception were discovered. CLR, θπ ratio, , and XP-EHH methods were used to detect the candidate signatures of positive selection in Bashan cattle. Among the identified genes, most of the enriched signal pathways were related to environmental information processing, biological systems, and metabolism. We mainly reported genes related to the nervous system (, , , , and ), immune (, , , and ), and reproduction (, , , and ). Our findings will be significant in understanding the molecular basis underlying phenotypic variation of breed-related traits and improving productivity in Bashan cattle.

Sun L ，Qu K ，Liu Y ，Ma X ，Chen N ，Zhang J ，Huang B ，Lei C ... -  《-》

Whole-Genome Resequencing of Xiangxi Cattle Identifies Genomic Diversity and Selection Signatures.

Understanding the genetic diversity in Xiangxi cattle may facilitate our efforts toward further breeding programs. Here we compared 23 Xiangxi cattle with 78 published genomes of 6 worldwide representative breeds to characterize the genomic variations of Xiangxi cattle. Based on clustering models in population structure analysis, we displayed that Xiangxi cattle had a mutual genome ancestor with Chinese indicine, Indian indicine, and East Asian taurine. Population genetic diversity was analyzed by four methods (nucleotide diversity, inbreeding coefficient, linkage disequilibrium decay and runs of homozygosity), and we found that Xiangxi cattle had higher genomic diversity and weaker artificial selection than commercial breed cattle. Using four testing methods (θπ, CLR, , and XP-EHH), we explored positive selection regions harboring genes in Xiangxi cattle, which were related to reproduction, growth, meat quality, heat tolerance, and immune response. Our findings revealed the extent of sequence variation in Xiangxi cattle at the genome-wide level. All of our fruitful results can bring about a valuable genomic resource for genetic studies and breed protection in the future.

Luo X ，Li J ，Xiao C ，Sun L ，Xiang W ，Chen N ，Lei C ，Lei H ，Long Y ，Long T ，Suolang Q ，Yi K ... -  《Frontiers in Genetics》

Genetic Diversity and Selective Signature in Dabieshan Cattle Revealed by Whole-Genome Resequencing.

Dabieshan cattle are a typical breed of southern Chinese cattle that have the characteristics of muscularity, excellent meat quality and tolerance to temperature and humidity. Based on 148 whole-genome data, our analysis disclosed the ancestry components of Dabieshan cattle with Chinese indicine (0.857) and East Asian taurine (0.139). The Dabieshan genome demonstrated a higher genomic diversity compared with the other eight populations, supported by the observed nucleotide diversity, linkage disequilibrium decay and runs of homozygosity. The candidate genes were detected by a selective sweep, which might relate to the fertility (, ), feed efficiency (), immune response (, , ), heat resistance (, , ), fat deposition () and the coat color (). We also identified the "East Asian taurine-like" segments in Dabieshan cattle, which might contribute to meat quality traits. The results revealed by the unique and valuable genomic data can build a foundation for the genetic improvement and conservation of genetic resources for indigenous cattle breeds.

Guan X ，Zhao S ，Xiang W ，Jin H ，Chen N ，Lei C ，Jia Y ，Xu L ... -  《Biology-Basel》