Project description:Here we describe a genome-wide analysis of copy number variations (CNVs) in Chinese domestic cattle by using array comparative genomic hybridization (array CGH) and quantitative PCR (qPCR). We conducted array CGH analysis on 30 male cattle individuals, animals from consisting of 12 breeds of Bos taurus/Bos indicus, 1 Bos grunniens and and two ones of Bubalus bubalis breeds for with beef, and/or dairy or dual purpose. We identified over 470 candidate CNV regions (CNVRs) in Bos B. taurus/B. indicus; 118 candidate CNV regions (CNVRs) in B. grunniens, 139 CNVRs in B. bubalis. Furthermore, based on the Y haplotypes of B. taurus/ B. indicus, Wwe also identified 69, 337, and 251 candidate CNV regions (CNVRs) in the sub-groups of Y1, Y2 and Y3 haplotypes.
Project description:Environmental heat stress negatively impacts the cattle health and productivity. It compromises the immune defense mechanisms and metabolic functions there by increasing the risk of diseases and poor productive performances. Compared to environmentally sensitive Bos taurus breeds, Bos indicus cattle breeds thrive better in tropical climates due to their heat tolerance; however, accelerating climate extremes now threaten even these resilient animals. To explore their underlying coping mechanisms, the present study mapped genome-wide gene expression changes in the B. indicus Hariana breed during heat exposure. The results indicated activation of set of gene clusters activated under stress. The functional characterization indicated molecular networks that suggested potential heat tolerance mechanisms.
Project description:Genomic structural variation is an important and abundant source of genetic and phenotypic variation. Here we describe the first systematic and genome-wide analysis of copy number variations (CNVs) in modern domesticated cattle using array comparative genomic hybridization (array CGH), quantitative PCR (qPCR) and fluorescent in situ hybridization (FISH). The array CGH panel included 90 animals from 11 Bos taurus, 3 Bos indicus and 3 composite breeds for beef, dairy or dual purpose. We identified over 200 candidate CNV regions (CNVRs) in total and 177 within known chromosomes, which harbor or are adjacent to gains or losses. These 177 high-confidence CNVRs cover 28.1 mega bases or ~1.07% of the genome. Over 50% of the CNVRs (89/177) were found in multiple animals or breeds and analysis revealed breed-specific frequency differences and reflected aspects of the known ancestry of these cattle breeds. Selected CNVs were further validated by independent methods using qPCR and FISH. Approximately 67% of the CNVRs (119/177) completely or partially span cattle genes and 61% of the CNVRs (108/177) directly overlap with segmental duplications. The CNVRs span about 400 annotated cattle genes that are significantly enriched for specific biological functions such as immunity, lactation, reproduction and rumination. Multiple gene families, including ULBP, have gone through ruminant lineage-specific gene amplification. We detected and confirmed marked differences in their CNV frequencies across diverse breeds, indicating that some cattle CNVs are likely to arise independently in breeds and contribute to breed differences. Our results provide a valuable resource beyond microsatellites and single nucleotide polymorphisms to explore the full dimension of genetic variability for future cattle genomic research.
Project description:Genomic structural variation is an important and abundant source of genetic and phenotypic variation. Here we describe the first systematic and genome-wide analysis of copy number variations (CNVs) in modern domesticated cattle using array comparative genomic hybridization (array CGH), quantitative PCR (qPCR) and fluorescent in situ hybridization (FISH). The array CGH panel included 90 animals from 11 Bos taurus, 3 Bos indicus and 3 composite breeds for beef, dairy or dual purpose. We identified over 200 candidate CNV regions (CNVRs) in total and 177 within known chromosomes, which harbor or are adjacent to gains or losses. These 177 high-confidence CNVRs cover 28.1 mega bases or ~1.07% of the genome. Over 50% of the CNVRs (89/177) were found in multiple animals or breeds and analysis revealed breed-specific frequency differences and reflected aspects of the known ancestry of these cattle breeds. Selected CNVs were further validated by independent methods using qPCR and FISH. Approximately 67% of the CNVRs (119/177) completely or partially span cattle genes and 61% of the CNVRs (108/177) directly overlap with segmental duplications. The CNVRs span about 400 annotated cattle genes that are significantly enriched for specific biological functions such as immunity, lactation, reproduction and rumination. Multiple gene families, including ULBP, have gone through ruminant lineage-specific gene amplification. We detected and confirmed marked differences in their CNV frequencies across diverse breeds, indicating that some cattle CNVs are likely to arise independently in breeds and contribute to breed differences. Our results provide a valuable resource beyond microsatellites and single nucleotide polymorphisms to explore the full dimension of genetic variability for future cattle genomic research. The custom aCGH chips that interrogated the whole genome CNVs were build for 90 cattles from diverse breeds, with Hereford L1 Dominette 01449 as refference sample.
Project description:Copy number variations (CNVs) have been demonstrated as crucial substrates for evolution, adaptation and breed formation. Chinese indigenous cattle breeds exhibit a broad geographical distribution and diverse environmental adaptability. Here, we analyzed the population structure and adaptation to high altitude of Chinese indigenous cattle based on genome-wide CNVs derived from the high-density BovineHD SNP array. We successfully detected the genome-wide CNVs of 318 individuals from 24 Chinese indigenous cattle breeds and 37 yaks as outgroups. A total of 5,818 autosomal CNV regions (683 bp - 4,477,860 bp in size), covering ~14.34% of the bovine genome (UMD3.1), were identified, showing abundant CNV resources. Neighbor-joining clustering, principal component analysis (PCA), and population admixture analysis based on these CNVs support that most Chinese cattle breeds are hybrids of Bos taurus taurus (hereinafter to be referred as Bos taurus) and Bos taurus indicus (Bos indicus). The distribution patterns of the CNVs could to some extent be related to the geographical backgrounds of the habitat of the breeds, and admixture among cattle breeds from different districts. We analyzed the selective signatures of CNVs positively involved in high-altitude adaptation using pairwise Fst analysis within breeds with a strong Bos taurus background (taurine-type breeds) and within Bos taurus×Bos indicus hybrids, respectively. CNV-overlapping genes with strong selection signatures (at top 0.5% of Fst value), including LETM1 (Fst = 0.490), TXNRD2 (Fst=0.440) and STUB1 (Fst=0.420) within taurine-type breeds, and NOXA1 (Fst = 0.233), RUVBL1 (Fst=0.222) and SLC4A3 (Fst=0.154) within hybrids, were potentially involved in the adaptation to hypoxia. Thus, we provide a new profile of population structure from the CNV aspects of Chinese indigenous cattle and new insights into high-altitude adaptation in cattle.
Project description:The Gayal (Bos frontalis) is a rare semi-domesticated cattle in China. Gayal has typical beef body shape and good meat production performance. Compared with other cattle species, it has the characteristics of tender meat and extremely low fat content. To explore the underlying mechanism responsible for the differences of meat quality between different breeds, the longissimus dorsi muscle (LM) from Gayal and Banna cattle (Bos taurus) were investigated using transcriptome analysis. The gene expression profiling identified 638 differentially expressed genes (DEGs) between LM muscles from Gayal and Banna cattle. Gene Ontology (GO) enrichment of biological functions and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the gene products were mainly involved in the PPAR signaling pathway, lipid metabolism and amino acid metabolism pathway. Protein-protein interaction(PPI) network analysis showed APOB, CYP7A1, THBS2, ITGAV, IGFBP1 and IGF2R may have great impact on meat quality characteristics of Gayal. Moreover, three transcription factors, FOXA2, NEUROG2, and RUNX1, which may affect meat quality by regulating the expression of genes related to muscle growth and development have also been found. In summary, our research reveals the molecular mechanisms that cause Gayal meat quality characteristics. It will contribute to improving meat quality of cattle through molecular breeding.
Project description:Heat stress is a critical environmental factor that adversely affects the health and productivity of cattle. It leads to substantial declines in productivity and compromises immune function, thereby increasing susceptibility to disease. Crossbred cattle (Bos indicus × Bos taurus) are known for their enhanced productivity. However, they are relatively vulnerable to environmental stressors. In recent years, the intensification of global warming and associated climatic extremes has further heightened their risk of heat stress. In this context, the present study investigated the underlying biological responses to heat stress through genome-wide expression analysis in Vrindavani crossbred cattle. The results identified sets of genes activated during heat stress and subsequent functional characterization revealed key molecular mechanisms of thermal stress response in these animals.