Project description:Circular RNAs (circRNAs) have been identified in various tissues and cell types from human, monkey, porcine and mouse. However, expression profile of circRNAs across cattle muscle development has never been investigated. Here, we examine the expression of circRNA in cattle skeletal muscle at embryonic stage and adult stage, exhibiting the first report of circRNA in the cattle muscle development of a large animal. 12,981 circRNAs are identified and annotated in Qinchuan cattle muscle tissues, including 530 circular intronic RNAs (ciRNAs). We discovered that one parental gene could generate multiple circRNA isoforms with only one or two circRNA isoforms being expressed at higher levels, and several host genes produced different alternative circularization numbers between different muscle development stages. The most circRNA candidates contained two to seven exons, and the genomic distance of the back-splicing site was generally no more than 50 kb. The flanking intron length of most circRNAs was not more than 105 nt and the mean length of upstream or downstream flanking intron was about 11,000 nt. Real-time quantitative PCR (qPCR) analysis confirmed the expression profile of these circRNAs, including several highly abundant circRNAs, and a subset of differently expressed circRNAs according to the high-throughput RNA sequencing (RNA-seq) data. These results display that an abundant circRNAs are dynamically expressed in a spatio-temporal manner in cattle muscle, indicating important and diverse functions during mammalian muscle development.
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:The transcriptome signature of peripheral blood mononuclear cells (PBMCs) of Ladakhi cattle adapted to high altitude vis a vis Sahiwal cattle adapted to the arid/semi-arid region at mean sea level was established using bovine expression microarray chips. The transcriptome analysis of PBMCs from these cattle types living at two distinct altitudes, resulted in identification of several hundred differentially expressed genes, biological processes, molecular functions and pathways.
Project description:Structural and functional impacts of copy number variations (CNVs) on livestock genomes are not yet well understood. In this study, we have identified 1853 CNV regions (CNVRs) using population-scale sequencing data generated from 75 cattle of 8 breeds (Holstein, Angus, Jersey, Limousin, Romagnola, Brahman, Gir and Nelore). Individual genome sequence coverage ranged from 4 to 30 fold, with a mean of 11.8 fold. A total of 3.1% (87.5 Mb) of the cattle genome is predicted to be copy number variable, representing a substantial increase over the previous estimates (~2%). This dataset was highly correlated with array CGH data (r2 = 0.761) and was validated to be accurate with an estimated 12% false positive rate and a 19% false negative rate based on qPCR and array CGH, respectively. Hundreds of CNVs were found to be either breed specific or differentially variable across breeds, including the RICTOR gene in dairy breeds and the PNPLA3 gene in the beef breeds. In contrast, clusters of the PRP and PAG genes are duplicated in all sequenced animals, implicating that subfunctionalization, neofunctionalization or overdominance play a role in diversifying these fertility related genes. Further population-genetic analyses based on CNVs revealed the population structures of these taurine and indicine breeds and uncovered hundreds of positively selected CNV candidates near important functional genes. These CNV results provide a new glimpse of diverse selections during cattle speciation, domestication, breed formation, and recent genetic improvement.
Project description:Bovine Viral Diarrhea Virus (BVDV) is an endemic virus of North American cattle populations with significant economic and animal health impacts. While BVDV infection has a myriad of clinical manifestations, a unique and problematic outcome is the establishment of a persistently infected (PI) animal following in-utero viral infection. While it is well established that PI animals serve as a constant reservoir of BVDV, the mechanism for the maintained infection remains unknown despite multiple theories. The purpose of this study was to use transcriptome analysis to further define long term immune status of adult PI cattle and offer insight into the potential mechanistic establishment of persistent BVDV infection, in utero. Peripheral blood mononuclear cells were collected from PI beef cattle (N=6) and uninfected controls (N=6) for targeted RNAseq analysis conducted using 54 genes of interest and followed by pathway enrichment analysis. Analysis revealed 29 differentially expressed genes (FDR < 0.05, fold change > 2) representing 14 significant KEGG pathways between PI and control animals (FDR < 0.05). Transcriptome changes indicate chronic upregulation of interferon gamma (IFNG) with unexpected expression of related genes, suggesting a maintained stimulation of the PI immune system resulting in virus-mediated dysregulation of immune function.
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:JC polyomavirus (circular genome) contains two opposite coding regions separated by the regulator non-coding control region (NCCR). NCCR rearrangements and missense mutations in the viral capsid protein VP1 gene differentiate JCV prototype genomes recovered from PML lesions from archetype urine strains. To further investigate the emerging variability of JCV populations in PML, we deep sequenced JCV whole genome recovered from CNS and/or urine samples from HIV- and non HIV-infected PML patients, using single-molecule real-time sequencing (PacBio, Pacific Biosciences). Phylogenetic analysis showed that PML strains distributed among 6 of 7 known genotypes. Whole genome single molecule sequencing provides insight in the genesis of JCV neurotropic populations.