Assessing Genomic Diversity and Productivity Signatures in Dianzhong Cattle by Whole-Genome Scanning.

Dianzhong cattle is a classic Chinese indigenous cattle breed with historical records dating back to 200 BC. But with its genomic differences having not been clearly elucidated, the quest for genomic characterization will be an essential step towards understanding the genomic basis of productivity and adaptation to survival under Chinese farming systems. Here we compared 10 Dianzhong cattle (four newly sequenced and six downloaded) with 29 published genomes of three underlying ancestral populations (Chinese zebu, Indian zebu, and Yanbian cattle) to characterize the genomic variations of Dianzhong cattle. Dianzhong cattle has a high nucleotide diversity (0.0034), second only to Chinese zebu. Together with analyses of linkage disequilibrium decay and runs of homozygosity, Dianzhong cattle displayed higher genomic diversity and weaker artificial selection compared with Yanbian cattle. From a selective sweep analysis by four methods (st, π-ratio, XP-CLR, and XP-EHH), the positive selective signals were mainly manifested in candidate genes and pathways related to heat resistance, growth and development, fat deposition, and male reproduction. Missense mutations were detected in candidate genes, (c.944C > A and p.Ala315Glu), (c.473A > G and p.Lys158Arg), and (rs460251486, rs722912933, and rs517668236), which related to heat resistance, fat deposition, and spermatogenesis, respectively. Our findings unravel, at the genome-wide level, the unique diversity of Dianzhong cattle while emphasizing the opportunities for improvement of livestock productivity in further breeding programs.

Zhang X ，Qu K ，Jia P ，Zhang J ，Liu J ，Lei C ，Huang B ... -  《Frontiers in Genetics》

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》

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》

Whole Genome Scan and Selection Signatures for Climate Adaption in Yanbian Cattle.

Yanbian cattle is inhabitant of North of China, exhibiting many phenotypic features, such as long, dense body hair, and abundant intramuscular fat, designed to combat the extreme cold climate adaption. In the current study, we studied the cold tolerance of nine Yanbian cattle by whole genome resequencing and compared with African tropical cattle, N'Dama, as a control group. Yanbian cattle was aligned to the Bos taurus reference genome (ARS-UCD1.2) yielding an average of 10.8 fold coverage. The positive selective sweep analysis for the cold adaption in Yanbian cattle were analyzed using composite likelihood ratio (CLR) and nucleotide diversity (θπ), resulting in 292 overlapped genes. The strongest selective signal was found on BTA16 with potential mutation in CORT gene, a regulatory gene of primary hormone in the hypothalamic-pituitary-adrenal (HPA) axis, is reported to be associated with the cold stress, representedfour missense mutations (c.269C > T, p.Lys90Ile; c.251A > G, p.Glu84Gly; c.112C > T, p.Pro38Ser; c.86G > A, p.Pro29His). Meanwhile another gene on BTA6, showed significantly higher selective sweep signals for a cold adapted trait for hair follicle and length development, (fibroblast growth factor 5) with a missense mutation (c.191C > T, p.Ser64Phe). Moreover, cold adapted Yanbian cattle was statistically compared with the hot adapted N'Dama cattle, a taurine cattle reported to show superior heat tolerance than zebu cattle, making them better adapted to the hot regions of Africa. XP-CLR, Fst, and θπ ratio were used to compare both breeds, yielding 487, 924, and 346 genes respectively. Among the 12 overlapped genes, () (c.638A > G, p.Lys 213Arg) involved in fat digestion and absorption plays an important role in membrane transport of long-chain fatty acid and its expression could increase in cold exposure. Henceforth, our study provides a novel genetic insights into the cold climate adaptation of Yanbian cattle and identified three candidate genes (, , ), which can add to an understanding of the cold climate adaptation of Yanbian cattle.

Shen J ，Hanif Q ，Cao Y ，Yu Y ，Lei C ，Zhang G ，Zhao Y ... -  《Frontiers in Genetics》

The genome landscape of indigenous African cattle.

The history of African indigenous cattle and their adaptation to environmental and human selection pressure is at the root of their remarkable diversity. Characterization of this diversity is an essential step towards understanding the genomic basis of productivity and adaptation to survival under African farming systems. We analyze patterns of African cattle genetic variation by sequencing 48 genomes from five indigenous populations and comparing them to the genomes of 53 commercial taurine breeds. We find the highest genetic diversity among African zebu and sanga cattle. Our search for genomic regions under selection reveals signatures of selection for environmental adaptive traits. In particular, we identify signatures of selection including genes and/or pathways controlling anemia and feeding behavior in the trypanotolerant N'Dama, coat color and horn development in Ankole, and heat tolerance and tick resistance across African cattle especially in zebu breeds. Our findings unravel at the genome-wide level, the unique adaptive diversity of African cattle while emphasizing the opportunities for sustainable improvement of livestock productivity on the continent.

Kim J ，Hanotte O ，Mwai OA ，Dessie T ，Bashir S ，Diallo B ，Agaba M ，Kim K ，Kwak W ，Sung S ，Seo M ，Jeong H ，Kwon T ，Taye M ，Song KD ，Lim D ，Cho S ，Lee HJ ，Yoon D ，Oh SJ ，Kemp S ，Lee HK ，Kim H ... -  《GENOME BIOLOGY》