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: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:Copy number variations (CNVs) affect a wide range of phenotypic traits; however, CNVs in or near segmental duplication regions are often intractable. Using a read depth approach based on next-generation sequencing, we examined genome-wide copy number differences among five taurine (three Angus, one Holstein and one Hereford) and one indicine (Nelore) cattle. Within mapped chromosomal sequence, we identified 1,265 CNV regions comprising ~55.6 Mbp sequence-476 of which (~38%) have not previously been reported. We validated this sequence-based CNV call set with aCGH, qPCR and FISH, achieving a validation rate of 82% and a false positive rate of 8%. We further estimated absolute copy numbers for genomic segments and annotated genes in each individual. Surveys of the top 25 most variable genes revealed that the Nelore individual had the lowest copy numbers in 13 cases (~52%, chi squared test; p value <0.05). In contrast, genes related to pathogen- and parasite-resistance, such as CATHL4 and ULBP17, were highly duplicated in the Nelore individual relative to the taurine cattle, while genes involved in lipid transport and metabolism, including APOL3 and FABP2, were highly duplicated in the beef breeds. These CNV regions also harbor genes like BPIFA2A (BSP30A) and WC1, suggesting that some CNVs may be associated with breed-specific differences in adaptation, health, and production traits. By providing the first individualized cattle CNV and segmental duplication maps and genome-wide gene copy number estimates, we enable future CNV studies into highly duplicated regions in the cattle genome. 5 NimbleGen Bos Taurus UMD3 custom 2.1M whole genome high density aCGH
Project description:Copy number variations (CNVs) affect a wide range of phenotypic traits; however, CNVs in or near segmental duplication regions are often intractable. Using a read depth approach based on next-generation sequencing, we examined genome-wide copy number differences among five taurine (three Angus, one Holstein and one Hereford) and one indicine (Nelore) cattle. Within mapped chromosomal sequence, we identified 1,265 CNV regions comprising ~55.6 Mbp sequence-476 of which (~38%) have not previously been reported. We validated this sequence-based CNV call set with aCGH, qPCR and FISH, achieving a validation rate of 82% and a false positive rate of 8%. We further estimated absolute copy numbers for genomic segments and annotated genes in each individual. Surveys of the top 25 most variable genes revealed that the Nelore individual had the lowest copy numbers in 13 cases (~52%, chi squared test; p value <0.05). In contrast, genes related to pathogen- and parasite-resistance, such as CATHL4 and ULBP17, were highly duplicated in the Nelore individual relative to the taurine cattle, while genes involved in lipid transport and metabolism, including APOL3 and FABP2, were highly duplicated in the beef breeds. These CNV regions also harbor genes like BPIFA2A (BSP30A) and WC1, suggesting that some CNVs may be associated with breed-specific differences in adaptation, health, and production traits. By providing the first individualized cattle CNV and segmental duplication maps and genome-wide gene copy number estimates, we enable future CNV studies into highly duplicated regions in the cattle genome.
Project description:We have generated open-chromatin profiles for liver, muscle, and hypothalamus of indicine cattle through ATAC-seq. Using robust methods for motif discovery, motif enrichment and transcription factor binding sites, we identified potential master regulators of the epigenomic profile in these three tissues, namely HNF1, MEF2 and NFYA factors, respectively. Integration with transcriptomic data allowed us to predict their target genes showing a significant recovery of confirmed targets across species.
Project description:The Toll-like receptor (TLR) and peptidoglycan recognition protein 1 (PGLYRP1) genes play key roles in the innate immune systems of mammals. While the TLRs recognize a variety of invading pathogens and induce innate immune responses, PGLYRP1 is directly microbicidal. We used custom allele-specific assays to genotype and validate 220 diallelic variants, including 54 nonsynonymous SNPs in 11 bovine innate immune genes (TLR1-TLR10, PGLYRP1) for 37 cattle breeds. Bayesian haplotype reconstructions and median joining networks revealed haplotype sharing between Bos taurus taurus and Bos taurus indicus breeds at every locus, and we were unable to differentiate between the specialized B. t. taurus beef and dairy breeds, despite an average polymorphism density of one locus per 219 bp. Ninety-nine tagSNPs and one tag insertion-deletion polymorphism were sufficient to predict 100% of the variation at all 11 innate immune loci in both subspecies and their hybrids, whereas 58 tagSNPs captured 100% of the variation at 172 loci in B. t. taurus. PolyPhen and SIFT analyses of nonsynonymous SNPs encoding amino acid replacements indicated that the majority of these substitutions were benign, but up to 31% were expected to potentially impact protein function. Several diversity-based tests provided support for strong purifying selection acting on TLR10 in B. t. taurus cattle. These results will broadly impact efforts related to bovine translational genomics.