Ningbo Chen

Whole-genome resequencing reveals world-wide ancestry and adaptive introgression events of domesticated cattle in East Asia

Cattle domestication and the complex histories of East Asian cattle breeds warrant further investigation. Through analysing the genomes of 49 modern breeds and eight East Asian ancient samples, worldwide cattle are consistently classified into five continental groups based on Y-chromosome haplotypes and autosomal variants. We find that East Asian cattle populations are mainly composed of three distinct ancestries, including an earlier East Asian taurine ancestry that reached China at least ~3.9 kya, a later introduced Eurasian taurine ancestry, and a novel Chinese indicine ancestry that diverged from Indian indicine approximately 36.6–49.6 kya. We also report historic introgression events that helped domestic cattle from southern China and the Tibetan Plateau achieve rapid adaptation by acquiring ~2.93% and ~1.22% of their genomes from banteng and yak, respectively. Our findings provide new insights into the evolutionary history of cattle and the importance of introgression in adaptation of cattle to new environmental challenges in East Asia.There are various indigenous cattle breeds in East Asia which have a complex history. Here, the authors analyse the genomes of 49 modern breeds and eight ancient samples and identify three distinct ancestries and multiple adaptive introgressions from other bovine species.

Population structure and ancestry of Qinchuan cattle

The aim of this study was to estimate population structure and ancestry of Qinchuan cattle by genotyping 27 individuals using the GeneSeek HD 77k BeadChip, and another 1355 cattle representing breeds distributed worldwide, which had been genotyped using the Illumina Bovine 50k BeadChip. Qinchuan cattle were characterized by a dominant Bos taurus ancestry, accompanied by a considerable proportion of Bos indicus ancestry based on principal components analysis and supervised admixture analysis. A small proportion of Bos javanicus ancestry was detected as well. A similar admixture pattern in both Qinchuan and Turkish cattle breeds reflects their similar degrees of zebu introgression. Our study presents a relatively clear view of the population structure and ancestry of Qinchuan cattle, serving to benefit our understanding of this breed and leading to better targeted conservation approaches moving forward.

Polymorphisms in MX2 Gene Are Related with SCS in Chinese Dairy Cows

ABSTRACT Viral infections can play direct or indirect roles in the etiology of the bovine mastitis. Mx dynamin-like GTPase 2 (MX2) gene is a main effector of the antiviral innate immune defense mediated by type I interferon (IFN I), which was demonstrated to confer positive antiviral responses to many viruses. Given the importance of the MX2 in modulating the host immune response, MX2 gene may be a suitable candidate gene for studying disease resistance in dairy cattle. Here, we scanned the sequence variation of the MX2 gene in Chinese indigenous cattle breeds. Twenty-three previously reported SNPs were identified. To further analyze the effects of SNPs detected on mastitis disease, analysis of two SNPs (g.787527 C > T and g.787610 T > C) from 297 Chinese Holstein cows revealed a significant association with somatic cell score (SCS). Although functional studies are necessary to ascertain whether these two SNPs are causal polymorphisms or merely in linkage with the true causal SNPs, implementation of these two SNPs as genetic markers in the dairy industry may be beneficial in selecting individuals with lower SCS.

HSFY and ZNF280BY show copy number variations within 17 water buffalo populations.

Recent transcriptomic analysis of the bovine Y chromosome revealed abundant presence of multi-copy protein coding gene families on the male-specific region of the Y chromosome (MSY). Copy number variations (CNVs) of several MSY genes are closely related to semen quality and male reproduction in cattle. However, the CNVs of MSY genes in water buffalo are largely unknown. Therefore, this study aimed to investigate the CNVs of HSFY and ZNF280BY of 298 buffaloes from 17 populations distributed in China, Vietnam and Laos using quantitative PCR. Our results revealed that the median copy numbers of the HSFY and ZNF280BY genes were 47 (ranging from 20 to 145) and 269 (ranging from 73 to 974) respectively. In conclusion, this study indicated that HSFY and ZNF280BY showed abundant CNVs within swamp buffalo populations.

Analysis of Genetic Diversity and Structure of Guanzhong Horse Using Microsatellite Markers

ABSTRACT To determine the genetic diversity and validate the pedigree record of Chinese Guanzhong horse, 67 individuals were genotyped with eight microsatellite markers. In our study, the mean observed and expected heterozygosities were 0.51 and 0.66, respectively. The mean observed number of alleles for the Guanzhong horse was 3.88. Nonetheless, the total value of FST multiloci clearly indicates that about 0.5% of overall genetic variation is due to line founder differences, while differences among individuals are responsible for the remaining 99.5%. In addition, the polymorphic information content (PIC) result showed that five loci (HTG7, HMS7, HMS2, AHT4, and HMS6) were highly polymorphic (PIC > 0.5) and three loci (HMS3, HTG6, and COR071) were moderate polymorphic (PIC > 0.25). Genetic distances and cluster analysis showed that the genetic relationship among 67 Guanzhong horse was generally consistent with pedigree recorded. Our results not only evaluated the genetic diversity of Chinese Guanzhong horse, but also suggested that the eight microsatellite markers might be used as subservient markers for parentage verification and individual identification in the Guanzhong horse.

Two Novel SNPs of PPARγ Significantly Affect Weaning Growth Traits of Nanyang Cattle

ABSTRACT Peroxisome-proliferator-activated receptor gamma (PPARγ) is a key transcription factor that controls adipocyte differentiation and energy in mammals. Therefore, PPARγ is a potential factor influencing animal growth traits. This study primarily evaluates PPARγ as candidate gene for growth traits of cattle and identifies potential molecular marker for cattle breeding. Per previous studies, PPARγ mRNA was mainly expressed at extremely high levels in adipose tissues as shown by quantitative real-time polymerase chain reaction analysis. Three novel SNPs of the bovine PPARγ gene were identified in 514 individuals from six Chinese cattle breeds: SNP1 (AC_000179.1 g.57386668 C > G) in intron 2 and SNP2 (AC_000179.1 g.57431964 C > T) and SNP3 (AC_000179.1 g.57431994 T > C) in exon 7. The present study also investigated genetic characteristics of these SNP loci in six populations. Association analysis showed that SNP1 and SNP3 loci significantly affect weaning growth traits, especially body weight of Nanyang cattle. These results revealed that SNP1 and SNP3 are potential molecular markers for cattle breeding.