Retinoid-dependent mRNA expression and poly-(A) contents in bovine oocytes meiotically arrested and/or matured in vitro.
The presence of retinoic acid (RA) during in vitro maturation (IVM) improves bovine oocyte quality and developmental potential. In this work, we investigated the underlying molecular mechanisms. Cumulus-oocyte complexes were meiotically arrested by roscovitine and/or matured in defined medium containing RA, 1% ethanol (vehicle), or no additives. Cumulus-free oocytes were analyzed for poly-(A) mRNA contents and relative mRNA expression of genes involved in cell cycle regulation (cyclin B1 and H1) and antioxidative defence (Mn-superoxide dismutase and glucose-6-phosphate dehydrogenase). Poly-(A) mRNA increased after meiotic inhibition and decreased with IVM completion, both in meiotically arrested and permissively matured oocytes, i.e., matured without previous meiotic arrest. RA dramatically increased poly-(A) mRNA in meiotically arrested oocytes, but more than half of the poly-(A) mRNA disappeared during maturation. Irrespective of oocyte origin, transcripts were detected for all the genes analyzed. IVM, with or without previous meiotic inhibition, increased expression of cyclin B1 and glucose-6-phosphate dehydrogenase, and decreased cyclin H1 and Mn-superoxide dismutase. Except for a decreasing of Mn-superoxide dismutase in meiotically arrested and matured oocytes, RA did not affect mRNA expression. Ethanol led to an abnormal poly-(A) mRNA profile and expression of all the genes analyzed. RA does not modify expression of cyclin B1 and HI genes in the bovine oocyte, and probably does not generate oxidative stress. In addition, RA enhanced mRNA amount as measured by poly-(A) mRNA contents.
Servicio Regional de Investigación y Desarrollo Agroalimentario, Area de Genética y Reproducción Animal, Camino de los Claveles, 604-Somio, Gijón 33203, Asturias, Spain. egomez@serida.org
Enrique
E
Gomez
Aida
A
Rodríguez
Felix
F
Goyache
Carmen
C
Díez
Luis
L
José Royo
Pedro N
PN
Moreira
José
J
Néstor Caamaño
Erica
E
Morán
Alfonso
A
Gutiérrez-Adán
D000818:Animals; D002417:Cattle; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D066298:In Vitro Techniques; D008540:Meiosis / Q000502:physiology*; D009865:Oocytes / Q000166:cytology / Q000502:physiology*; D047428:Protein Kinase Inhibitors / Q000378:metabolism; D011687:Purines / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D000077546:Roscovitine; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D014212:Tretinoin / Q000378:metabolism*
D047428:Protein Kinase Inhibitors; D011687:Purines; D012333:RNA, Messenger; D000077546:Roscovitine; D014212:Tretinoin; D005954:Glucosephosphate Dehydrogenase; D013482:Superoxide Dismutase; D018844:Cyclin-Dependent Kinases