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:Comparative microarray analysis of Rhipicephalus (Boophilus) microplus expression profiles of larvae pre-attachment and feeding adult female stages on Bos indicus and B. taurus cattle Global analysis of gene expression changes in R. microplus during larval, pre-attachment and early adult stages of its life cycle feeding on Bos indicus and Bos taurus cattle were compared using gene expression microarray analysis. Among the 13 601 R. microplus transcripts from BmiGI Version 2 we identified 297 up and 17 down regulated transcripts were differentially expressed between R. microplus feeding on tick resistant cattle [Bos indicus (Brahman)] compared to R. microplus feeding on tick susceptible cattle [Bos taurus (Holstein-Friesian)]. These include genes encoding enzymes involved in primary metabolism, and genes related to stress, defence, cell wall modification, cellular signaling, receptor and cuticle. Microarrays were validated by qRT-PCR analysis of selected transcripts including the validation of three housekeeping genes. The analysis of all tick stages under survey suggested a coordinated regulation of defence proteins, proteases, and protease inhibitors to achieve successful attachment and survival of R. microplus on different host breeds particularly Bos indicus cattle.
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.
Project description:Comparative microarray analysis of Rhipicephalus (Boophilus) microplus expression profiles of larvae pre-attachment and feeding adult female stages on Bos indicus and B. taurus cattle Global analysis of gene expression changes in R. microplus during larval, pre-attachment and early adult stages of its life cycle feeding on Bos indicus and Bos taurus cattle were compared using gene expression microarray analysis. Among the 13 601 R. microplus transcripts from BmiGI Version 2 we identified 297 up and 17 down regulated transcripts were differentially expressed between R. microplus feeding on tick resistant cattle [Bos indicus (Brahman)] compared to R. microplus feeding on tick susceptible cattle [Bos taurus (Holstein-Friesian)]. These include genes encoding enzymes involved in primary metabolism, and genes related to stress, defence, cell wall modification, cellular signaling, receptor and cuticle. Microarrays were validated by qRT-PCR analysis of selected transcripts including the validation of three housekeeping genes. The analysis of all tick stages under survey suggested a coordinated regulation of defence proteins, proteases, and protease inhibitors to achieve successful attachment and survival of R. microplus on different host breeds particularly Bos indicus cattle. The microarray was conducted by NimbleGen Systems Inc following the method reported by Saldivar [Saldivar L et al., Insect Mol Biol 2008, 17(6):597-606]. 10 samples: 2 larva, 2 pre-attachment larva in B. indicus and 2 in B. taurus, and 2 adult ticks in B. indicus and 2 in B. taurus
Project description:Genomic imprinting is an epigenetic mechanism that leads to parental-allele-specific gene expression. Approximately 150 imprinted genes have been identified in humans and mice but less than 30 genes have been described as imprinted in cattle. For the purpose of de novo identification of imprinted genes in bovine, we determined global monoallelic gene expression in brain, skeletal muscle, liver, kidney and placenta of day ~105 Bos taurus indicus X Bos taurus taurus F1 conceptuses using RNA sequencing. For this, we developed a bioinformatics pipeline to identify parental-specific SNPs after filtering A-to-I RNA editing sites. We identified 53 genes subject to monoallelic expression. A total of 23 are genes known to be imprinted in the cow and 7 are previously-characterized imprinted genes in human and/or mouse that have not be reported to be imprinted in cattle. Of the remaining 23 genes, we found that 10 are uncharacterized or unannotated transcripts located in known imprinting clusters, whereas the other 13 genes are distributed across the bovine genome and not close to any known imprinting clusters. To exclude potential cis-eQTL effects on allelic expression, we corroborated the parental specificity of monoallelic expression in day 86 Bos taurus taurus X Bos taurus taurus F1s and identified eight novel imprinted genes in bovine. Further, we identified 671 candidate A-to-I RNA editing sites and describe imprinted X inactivation in the bovine trophectoderm-derived CT1 cell line. Our results expand the imprinted gene list in bovine and demonstrate that monoallelic gene expression can be the result of cis-eQTL effect.
Project description:Latvia has two local Bos taurus breeds-Latvian Brown (LBG) and Latvian Blue (LZG)-characterized by a good adaptation to the local climate, longevity, and high fat and protein contents in milk. Since these are desired traits in the dairy industry, this study investigated the genetic background of the LBG and LZG breeds and identified the genetic factors associated with mastitis. Blood and semen samples were acquired, and whole genome sequencing was then performed to acquire a genomic sequence with at least 35× or 10× coverage. The heterozygosity, nucleotide diversity, and LD analysis indicated that LBG and LZG cows have similar levels of genetic diversity compared to those of other breeds. An analysis of the population structure revealed that each breed clustered together, but the overall differentiation between the breeds was small. The highest genetic variance was observed in the LZG breed compared with the LBG breed. Our results show that SNP rs721295390 is associated with mastitis in the LBG breed, and SNPs rs383806754, chr29:43998719CG>C, and rs462030680 are associated with mastitis in the LZG breed. This study shows that local Latvian LBG and LZG breeds have a pronounced genetic differentiation, with each one suggesting its own mastitis-associated SNP profile.
Project description:Given that different diets could alter cow milk yield and composition, the effects of different feed formula on milk extracellular vesicle (EV) miRNAs were detected. Cow milk EVs contained various small RNAs, including miRNAs, snRNAs, tiRNAs, Cis-regulatory elements, and piRNAs. Two hundred and seventy-six known bos taurus miRNAs were identified by sequencing in bovine milk EVs. There were 13 immune-related miRNAs in the top 20 miRNAs in milk EVs. Nine differently expressed known miRNAs were detected in responding to different feed formulations. Cow milk EVs are abundant of small RNAs, especially miRNAs, which might be closely related to the development of maternal mammary gland and neonatal immune maturity.