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: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: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: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:Background: The Malnad Gidda are unique dwarf Bos indicus cattle native to heavy rainfall Malnad and coastal areas of Karnataka in India. These cattle are highly adapted to harsh climatic conditions and are more resistant to Foot and Mouth disease as compared to other breeds of B.indicus. Since the first genome reference became available from B.taurus Hereford breed, only a few other breeds have been genotyped using high-throughput platforms. Also despite the known reports on high diversity within indicine breeds as compared to taurine breeds, only one draft genome of Nellore and horn transcriptome of Kankrej breed were sequenced at base level resolution. Because of the special characteristics Malnad Gidda possess, it becomes the choice of breed among many indicine cows to study at molecular level and genotyping. Results: Sequencing mRNA from the PBMCs isolated from blood of one selected Malnad Gidda bull resulted in generation of 55 million paired-end reads of 100bp length. Raw sequencing data is processed to trim the adaptor and low quality bases, and are aligned against the whole genome and transcript assemblies of Bos taurus UMD 3.1 and Bos indicus (Nellore breed) respectively. About 72% of the sequenced reads from our study could be mapped against the B.taurus genome where as only 41% of reads could be mapped against the Bos indicus transcript assembly. Transcript assembly from the alignment carried out against the annotated B.taurus UMD 3.1 genome resulted in identification of ~10,000 genes with significant expression (FPKM>1). In a similar analysis against the B.indicus Kankrej assembled transcripts we could identify only ~6,000 transcripts. From the variant analysis of the sequencing data we found ~10,000 SNPs in coding regions among which ~9,000 are novel and ~6,400 are amino acid changing. Conclusions: For the first time we have genotyped and explored the transcriptome of B.indicus Malnad Gidda breed. A comparative analysis of mapping the RNA-Seq data against the available reference genome and transcript sequences is demonstrated. An enhanced utility of transcript sequencing could be achieved by improving or completing the sequence assembly of any B.indicus breed to better characterize the indicine breeds for productivity features and selective breeding.
Project description:Tropical theileriosis in a cattle disease of global economic importance, caused by the tick-borne protozoan parasite Theileria annulata. Conventional control strategies are failing to contain the disease and an attractive alternative is the use of pre-existing genetic resistance or tolerance. However, tropical theileriosis tolerant cattle are less productive than some susceptible breeds. To combine resistance and production traits requires an understanding of the mechanisms involved in resistance. Therefore, we have compared the response of monocytes derived from tolerant (Sahiwals, Bos indicus) and susceptible (Holstein-Friesians, B. taurus) cattle to in vitro infection with T. annulata. Over 150 genes exhibited breed-specific differential expression during the course of infection and nearly one third were differentially expressed in resting cells, implying that there are inherent differences between monocytes from the breeds. Fifty sequences currently only match ESTs or are unique to the library used to generate the microarray. The differential expression of a selection of genes was validated by quantitative RT-PCR, e.g. CD9, prion protein and signal-regulatory protein alpha. A large proportion of the differentially expressed genes encode proteins expressed on the plasma membrane or in the extracellular space and cell adhesion was one of the major Gene Ontology biological processes identified. We therefore hypothesise that the breed-specific tolerance of Sahiwal cattle compared to Holstein-Friesians is due to the interaction of infected cells with other immune cells, which influences the immune response generated against T. annulata infection. The BoMP microarray is available from the ARK-Genomics facility (www.ark-genomics.org).
Project description:This experiment was undertaken to document changes in gene expression in the skin of tick-resistant Brahman (Bos indicus) and tick-susceptible Holstein-Friesian (Bos taurus) cattle prior to, and following, infestation with the cattle tick Rhipicephalus (Boophilus) microplus Experiment Overall Design: RNA was extracted from skin samples of tick-naïve cattle (animals with no previous R.microplus exposure) and tick-infested cattle after a period of successive, heavy infestations with R. microplus. Skin samples taken from tick-infested animals were taken at sites where tick larvae (approximately 24 h old) were attached to the skin sample. Skin samples were of 8 mm diameter and full skin thickness (approximately 10 mm). RNA samples from 12 animals (3 tick-naive Holstein-Friesian, 3 tick-naive Brahman, 3 tick-infested Holstein-Friesian and 3 tick-infested Brahman) were processed and hybridised to individual slides.