title: Genetic influence on the reduction in bovine embryo lipid content by l-carnitine.
abstract: The decreased rate of pregnancy obtained in cattle using frozen in vitro embryos compared with 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 breeds 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 examined in terms of 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. The response to l-carnitine was weaker in Jersey than in Holstein embryos. Our results thus show that genetics influence the response of bovine embryos to stimulation of mitochondrial metabolism.
authors.affiliation: Laboratory of Functional Genomics of Early Embryonic Development, Centre de Recherche en Biologie de la Reproduction, Institut des Nutraceutiques et des Aliments Fonctionnels, Faculté des Sciences de l'Agriculture et de l'Alimentation, Pavillon des Services, Université Laval, Québec G1V 0A6, Canada.
authors.forename: Luis
authors.initials: L
authors.lastname: Baldoceda
authors.affiliation: Laboratory of Functional Genomics of Early Embryonic Development, Centre de Recherche en Biologie de la Reproduction, Institut des Nutraceutiques et des Aliments Fonctionnels, Faculté des Sciences de l'Agriculture et de l'Alimentation, Pavillon des Services, Université Laval, Québec G1V 0A6, Canada.
authors.forename: Dominic
authors.initials: D
authors.lastname: Gagné
authors.affiliation: ThoMSon Mass Spectrometry Laboratory, Institute of Chemistry, University of Campinas, São Paulo, Campinas 13083-970, Brazil.
authors.forename: Christina Ramires
authors.initials: CR
authors.lastname: Ferreira
authors.affiliation: Laboratory of Functional Genomics of Early Embryonic Development, Centre de Recherche en Biologie de la Reproduction, Institut des Nutraceutiques et des Aliments Fonctionnels, Faculté des Sciences de l'Agriculture et de l'Alimentation, Pavillon des Services, Université Laval, Québec G1V 0A6, Canada.|Corresponding author. Email: claude.robert@fsaa.ulaval.ca.
authors.forename: Claude
authors.initials: C
authors.lastname: Robert
keywords: dairy breed; in vitro-produced embryo; lipid droplets; lipid profile; mitochondria