Project description:The decreased rate of pregnancy obtained in cattle using frozen in vitro embryos compared to in vivo embryos has been associated with over-accumulation of intracellular lipid, which causes cell damage during cryopreservation. It is believed that the higher lipid content of blastomeres of bovine embryos produced in vitro results in darker coloured cytoplasm which could be a consequence of impaired mitochondrial function. In this study, L-carnitine was used as a treatment to reduce embryonic lipid content by increasing metabolism in cultured bovine embryos. We have observed previously that in vivo embryos of different dairy breed collected from cows housed and fed under the same conditions differed in lipid content and metabolism. As such, breed effects between Holstein and Jersey were also accounted for general appearance, lipid composition, mitochondrial activity and gene expression. Adding L-carnitine to the embryo culture medium reduced the lipid content in both breeds due to increased mitochondrial activity. L-carnitine vs controls, in 4 replicates for each breed, with dye-swaps.
Project description:The decreased rate of pregnancy obtained in cattle using frozen in vitro embryos compared to in vivo embryos has been associated with over-accumulation of intracellular lipid, which causes cell damage during cryopreservation. It is believed that the higher lipid content of blastomeres of bovine embryos produced in vitro results in darker coloured cytoplasm which could be a consequence of impaired mitochondrial function. In this study, L-carnitine was used as a treatment to reduce embryonic lipid content by increasing metabolism in cultured bovine embryos. We have observed previously that in vivo embryos of different dairy breed collected from cows housed and fed under the same conditions differed in lipid content and metabolism. As such, breed effects between Holstein and Jersey were also accounted for general appearance, lipid composition, mitochondrial activity and gene expression. Adding L-carnitine to the embryo culture medium reduced the lipid content in both breeds due to increased mitochondrial activity.
Project description:In this study, we use mRNA-Seq to characterize and compare the leukocyte transcriptomes of Holstein, Jersey, and Cholistani with respect to variations in sequence, expression, and splicing. Poly A+ RNA are extracted from leukocytes of pools of blood drawn from cows of three different breeds, Holstein, Jersey, and Cholistani. The objective of the study is to compare sequence variation and gene expression of the three cattle breeds.
Project description:Some embryos display better survival potential to cryopreservation than others. The cause of such phenotype is still unclear and might be due to cell damage during cryopreservation, resulting from over-accumulation and composition of lipids. In cattle embryos, in vitro culture conditions have been shown to impact the number of lipid droplets within blastomeres. So far, the impact of breed on embryonic lipid content has not yet been studied. In this study were compared the colour, lipid droplet abundance, lipid composition, mitochondrial activity, and gene expression of in vivo collected Jersey breed embryos which are known to display poor performance post-freezing and in vivo Holstein embryos which have good cryotolerance. Holstein in vivo day 6 embryos vs Jersey in vivo day 6 embryos: 4 replicates of each breed, with dye-swap.
Project description:The objectives of the study were to use RNA-Seq to examine the effect of (i) breed and (ii) gradual weaning, on the whole blood mRNA transcriptome of artificially reared Holstein-Friesian and Jersey calves. The calves were gradually weaned over 14 days (day (d) -13 to d 0) and mRNA transcription was examined one day before gradual weaning was initiated (d -14), one day after weaning (d 1) and 8 days after weaning (d 8). RNA-seq analysis was carried out on RNA extracted from whole blood. Gradual weaning had no effect on gene expression (P>0.05).There were 550 differentially expressed genes at a false discovery rate of 10% and with a ≥1.5-fold change, between Holstein-Friesian and Jersey calves on d -14, 490 on d 1, and 411 on d 8. GOseq/KEGG pathway analysis showed that the cytokine-cytokine receptor interaction pathway and the neuroactive ligand-receptor interaction pathway were over-represented between breeds on all days (P<0.01; Q≤0.1). These results demonstrate that the gradual weaning practiced here does not compromise the welfare of artificially-reared dairy calves, evidenced by the lack of expression changes in any genes in response to gradual weaning. These data also suggest differences in cell signalling and immune responses between breeds.
Project description:MicroRNA expression in bovine satellite cells at 6th day of in vitro differentiation - myotubes (Hereford & Limousin vs Holstein-Freisian cattle)