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.

2016-08-17 | GSE77389 | GEO

bovine metagenome

Project description:Bos taurus Targeted Locus (Loci)

| PRJNA275356 | ENA

bovine gut metagenome

Project description:Bos mutus gastric substance Metagenome

| PRJNA1036001 | ENA

Fine mapping of genome activation in bovine embryos by RNA sequencing

Project description:During maternal-to-embryonic transition control of embryonic development gradually switches from maternal RNAs and proteins stored in the oocyte to gene products generated after embryonic genome activation (EGA). Detailed insight into the onset of embryonic transcription is obscured by the presence of maternal transcripts. Using the bovine model system, we established by RNA sequencing a comprehensive catalogue of transcripts in germinal vesicle and metaphase II oocytes, and in embryos at the 4-cell, 8-cell, 16-cell and blastocyst stages. These were produced by in vitro fertilization of Bos t. taurus oocytes with sperm from a Bos t. indicus bull to facilitate parent-specific transcriptome analysis. Transcripts from 12.4 to 13.7 M-CM-^W 10^3 different genes were detected in the various developmental stages. EGA was analyzed by i) detection of embryonic transcripts which are not present in oocytes; ii) detection of transcripts from the paternal allele; and iii) detection of primary transcripts with intronic sequences. These strategies revealed (i) 220, (ii) 937, and (iii) 6,848 genes to be activated from the 4-cell to the blastocyst stage. The largest proportion of gene activation, i.e. (i) 59%, (ii) 42%, and (iii) 58%, was found in 8-cell embryos, indicating major EGA at this stage. Gene ontology analysis of genes activated at the 4-cell stage identified categories related to translation, RNA processing and transport, consistent with preparation for major EGA. Our study provides the largest transcriptome data set of bovine oocyte maturation and early embryonic development and new insight into the timing of embryonic activation of specific genes. RNA-Seq profiles from pools of 10 ooytes/embryos from bovine Bos t. taurus GV and MII oocytes and a cross-breed of Bos t. taurus x Bos t. indicus from 4-cell, 8-cell, 16-cell and blastocysts generated using Illumina GAIIx

2014-02-09 | E-GEOD-52415 | biostudies-arrayexpress

bovine metagenome

Project description:Bos taurus breed:Angus Hereford Targeted Locus (Loci)

| PRJNA296393 | ENA