title: Effects of oocyte donor age and embryonic stage of development on transcription of genes coding for enzymes of the prostaglandins and progesterone synthesis pathways in bovine in vitro produced embryos.
abstract: The ability of early bovine embryos to produce prostaglandins (PGs) and progesterone (P4), and the role of these mediators in embryonic development and survival are poorly understood. In this study we tested the hypothesis that day 7 bovine embryos are able to transcribe genes coding for enzymes of the PGs (PTGS2, PGES, PGFS) and P4 (StAR, P450scc, 3β-HSD) synthesis pathways, and that transcription levels of these genes are associated with developmental progression and heifer age-related [pre-pubertal (PP) versus post-pubertal cyclic (C)] oocyte competence. Compared with C heifer oocytes, PP heifer oocytes showed a lower (P < 0.0001) in vitro blastocyst rate, but in embryos developing until day 7, heifer age had no effect on quality grade. Day 7 quality grade 1-2 embryos were selected for RNA extraction and gene transcription analysis by qRT-PCR, in a 2 × 2 factorial design [age (PP or C) × embryonic stage (compact morulae and early blastocysts, CM + EBL, or blastocysts and expanded blastocysts, BL + BEX); 15 embryos/group]. Transcription levels of PTGS2, PGES, PGFS, P450scc and 3β-HSD were not affected by heifer age but were higher (P < 0.01) in BL + BEX than in CM + EBL. In conclusion, the main limiting factor for embryo production from PP heifers is oocyte competence. Day 7 bovine embryos evidence transcription of genes coding for enzymes of PGs and P4 synthesis pathways, and transcription levels are associated with blastocyst differentiation. This prompts for an autocrine/paracrine action of PGs and P4 in early bovine embryonic development.
authors.affiliation: Reproduction and Obstetrics,CIISA,Faculty of Veterinary Medicine,University of Lisbon,Avenida da Universidade Técnica,Alto da Ajuda,1300-477 Lisboa,Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Torres
authors.affiliation: Reproduction and Obstetrics,CIISA,Faculty of Veterinary Medicine,University of Lisbon,Avenida da Universidade Técnica,Alto da Ajuda,1300-477 Lisboa,Portugal.
authors.forename: M
authors.initials: M
authors.lastname: Batista
authors.affiliation: Reproduction and Obstetrics,CIISA,Faculty of Veterinary Medicine,University of Lisbon,Avenida da Universidade Técnica,Alto da Ajuda,1300-477 Lisboa,Portugal.
authors.forename: P
authors.initials: P
authors.lastname: Diniz
authors.affiliation: Reproduction and Obstetrics,CIISA,Faculty of Veterinary Medicine,University of Lisbon,Avenida da Universidade Técnica,Alto da Ajuda,1300-477 Lisboa,Portugal.
authors.forename: E
authors.initials: E
authors.lastname: Silva
authors.affiliation: Reproduction and Obstetrics,CIISA,Faculty of Veterinary Medicine,University of Lisbon,Avenida da Universidade Técnica,Alto da Ajuda,1300-477 Lisboa,Portugal.
authors.forename: L
authors.initials: L
authors.lastname: Mateus
authors.affiliation: Reproduction and Obstetrics,CIISA,Faculty of Veterinary Medicine,Universidade de Lisboa,Avenida da Universidade Técnica,Alto da Ajuda,1300-477 Lisboa,Portugal.
authors.forename: L
authors.initials: L
authors.lastname: Lopes-da-Costa
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001755:Blastocyst / Q000502:physiology*; D002417:Cattle; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000235:genetics / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D005260:Female; D005307:Fertilization in Vitro; D018507:Gene Expression Regulation, Developmental; D008297:Male; D008423:Maternal Age; D018587:Oocyte Donation; D009865:Oocytes / Q000502:physiology*; D011374:Progesterone / Q000235:genetics / Q000378:metabolism*; D011453:Prostaglandins / Q000235:genetics / Q000378:metabolism*; D011627:Puberty
chemical_list: D011453:Prostaglandins; D011374:Progesterone; D015096:3-Hydroxysteroid Dehydrogenases; D002786:Cholesterol Side-Chain Cleavage Enzyme; D051546:Cyclooxygenase 2
keywords: Bovine; Embryo; Gene transcripts; Progesterone; Prostaglandins