title: Suboptimal culture conditions induce more deviations in gene expression in male than female bovine blastocysts.
abstract: BACKGROUND
  Since the development of in vitro embryo production in cattle, different supplements have been added to culture media to support embryo development, with serum being the most popular. However, the addition of serum during embryo culture can induce high birthweights and low viability in calves (Large Offspring Syndrome). Analysis of global gene expression in bovine embryos produced under different conditions can provide valuable information to optimize culture media for in vitro embryo production.
  
  
  RESULTS
  We used RNA sequencing to examine the effect of in vitro embryo production, in either serum-containing or serum-free media, on the global gene expression pattern of individual bovine blastocysts. Compared to in vivo derived embryos, embryos produced in serum-containing medium had five times more differentially expressed genes than embryos produced in serum-free conditions (1109 vs. 207). Importantly, in vitro production in the presence of serum appeared to have a different impact on the embryos according to their sex, with male embryos having three times more genes differentially expressed than their female counterparts (1283 vs. 456). On the contrary, male and female embryos produced in serum-free conditions showed the same number (191 vs. 192) of genes expressed differentially; however, only 44 of those genes were common in both comparisons. The pathways affected by in vitro production differed depending on the type of supplementation. For example, embryos produced in serum-containing conditions had a lower expression of genes related to metabolism while embryos produced in serum-free conditions showed aberrations in genes involved in lipid metabolism.
  
  
  CONCLUSIONS
  Serum supplementation had a major impact on the gene expression pattern of embryos, with male embryos being the most affected. The transcriptome of embryos produced in serum-free conditions showed a greater resemblance to that of in vivo derived embryos, although genes involved in lipid metabolism were altered. Male embryos appeared to be most affected by suboptimal in vitro culture, i.e. in the presence of serum.
authors.affiliation: Department of Reproduction, Obstetrics and Herd Health. Faculty of Veterinary Medicine, Ghent University, 9820, Merelbeke, Belgium. sonia.herasgarcia@ugent.be.
authors.forename: Sonia
authors.initials: S
authors.lastname: Heras
authors.affiliation: Laboratory of Pharmaceutical Biotechnology, Faculty of Pharmaceutical Sciences, Ghent University, 9000, Ghent, Belgium. Dieter.DeConinck@UGent.be.
authors.forename: Dieter I M
authors.initials: DI
authors.lastname: De Coninck
authors.affiliation: Department of Nutrition, Genetics and Ethology - Faculty of Veterinary Medicine, Ghent University, 9820, Merelbeke, Belgium. Mario.VanPoucke@UGent.be.
authors.forename: Mario
authors.initials: M
authors.lastname: Van Poucke
authors.affiliation: Department of Nutrition, Genetics and Ethology - Faculty of Veterinary Medicine, Ghent University, 9820, Merelbeke, Belgium. karen.goossens@ilvo.vlaanderen.be.|Current address: Institute for Agricultural and Fisheries Research (ILVO), Animal Sciences Unit, Scheldeweg 68, 9090, Melle, Belgium. karen.goossens@ilvo.vlaanderen.be.
authors.forename: Karen
authors.initials: K
authors.lastname: Goossens
authors.affiliation: Department of Reproduction, Obstetrics and Herd Health. Faculty of Veterinary Medicine, Ghent University, 9820, Merelbeke, Belgium. osvaldo.bogado@ugent.be.
authors.forename: Osvaldo
authors.initials: O
authors.lastname: Bogado Pascottini
authors.affiliation: Laboratory of Pharmaceutical Biotechnology, Faculty of Pharmaceutical Sciences, Ghent University, 9000, Ghent, Belgium. Filip.VanNieuwerburgh@UGent.be.
authors.forename: Filip
authors.initials: F
authors.lastname: Van Nieuwerburgh
authors.affiliation: Laboratory of Pharmaceutical Biotechnology, Faculty of Pharmaceutical Sciences, Ghent University, 9000, Ghent, Belgium. Dieter.Deforce@UGent.be.
authors.forename: Dieter
authors.initials: D
authors.lastname: Deforce
authors.affiliation: Department for Reproductive Medicine, Ghent University Hospital, 9000, Ghent, Belgium. Petra.DeSutter@UGent.be.
authors.forename: Petra
authors.initials: P
authors.lastname: De Sutter
authors.affiliation: Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, University of Antwerp, 2610, Wilrijk, Belgium. Jo.leroy@uantwerpen.be.
authors.forename: Jo L M R
authors.initials: JL
authors.lastname: Leroy
authors.affiliation: Dpto. Reproduccion Animal, Instituto Nacional de Investigación, y Tecnología Agraria y Alimentaria, INIA, 28040, Madrid, Spain. agutierr@inia.es.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Gutierrez-Adan
authors.affiliation: Department of Nutrition, Genetics and Ethology - Faculty of Veterinary Medicine, Ghent University, 9820, Merelbeke, Belgium. Luc.Peelman@UGent.be.
authors.forename: Luc
authors.initials: L
authors.lastname: Peelman
authors.affiliation: Department of Reproduction, Obstetrics and Herd Health. Faculty of Veterinary Medicine, Ghent University, 9820, Merelbeke, Belgium. Ann.VanSoom@UGent.be.
authors.forename: Ann
authors.initials: A
authors.lastname: Van Soom
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000378:metabolism*; D002417:Cattle; D018929:Cell Culture Techniques / Q000592:standards; D004622:Embryo, Mammalian / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D008297:Male; D012737:Sex Factors