In vivo and in vitro maturation of rabbit oocytes differently affects the gene expression profile, mitochondrial distribution, apoptosis and early embryo development.
In vivo-matured cumulus-oocyte complexes are valuable models in which to assess potential biomarkers of rabbit oocyte quality that contribute to enhanced IVM systems. In the present study we compared some gene markers of oocytes and cumulus cells (CCs) from immature, in vivo-matured and IVM oocytes. Moreover, apoptosis in CCs, nuclear maturation, mitochondrial reallocation and the developmental potential of oocytes after IVF were assessed. In relation to cumulus expansion, gene expression of gap junction protein, alpha 1, 43 kDa (Gja1) and prostaglandin-endoperoxide synthase 2 (Ptgs2) was significantly lower in CCs after in vivo maturation than IVM. In addition, there were differences in gene expression after in vivo maturation versus IVM in both oocytes and CCs for genes related to cell cycle regulation and apoptosis (V-Akt murine thymoma viral oncogene homologue 1 (Akt1), tumour protein 53 (Tp53), caspase 3, apoptosis-related cysteine protease (Casp3)), oxidative response (superoxide dismutase 2, mitochondrial (Sod2)) and metabolism (glucose-6-phosphate dehydrogenase (G6pd), glyceraldehyde-3-phosphate dehydrogenase (Gapdh)). In vivo-matured CCs had a lower apoptosis rate than IVM and immature CCs. Meiotic progression, mitochondrial migration to the periphery and developmental competence were higher for in vivo-matured than IVM oocytes. In conclusion, differences in oocyte developmental capacity after IVM or in vivo maturation are accompanied by significant changes in transcript abundance in oocytes and their surrounding CCs, meiotic rate, mitochondrial distribution and apoptotic index. Some of the genes investigated, such as Gja1, could be potential biomarkers for oocyte developmental competence in the rabbit model, helping improve in vitro culture systems in these species.
Department of Producción Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Ciudad Universitaria, s/n, 28040, Madrid, Spain.
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Arias-Álvarez
Department of Fisiología (Fisiología Animal), Facultad de Veterinaria, Universidad Complutense de Madrid, Ciudad Universitaria, s/n, 28040, Madrid, Spain.
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García-García
Department of Producción Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Ciudad Universitaria, s/n, 28040, Madrid, Spain.
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López-Tello
Department of Producción Agraria, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Politécnica de Madrid, Ciudad Universitaria, s/n, 28040, Madrid, Spain.
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Rebollar
Department of Reproducción Animal, Instituto Nacional de Investigación y Tecnología Agraria, Carretera de La Coruña, Kilómetro 5.9, 28040, Madrid, Spain.
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Gutiérrez-Adán
Department of Fisiología (Fisiología Animal), Facultad de Veterinaria, Universidad Complutense de Madrid, Ciudad Universitaria, s/n, 28040, Madrid, Spain.
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Lorenzo
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D054885:Cumulus Cells / Q000378:metabolism; D047108:Embryonic Development / Q000502:physiology*; D005260:Female; D020869:Gene Expression Profiling; D059471:In Vitro Oocyte Maturation Techniques / Q000379:methods*; D008928:Mitochondria / Q000502:physiology*; D009865:Oocytes / Q000254:growth & development* / Q000378:metabolism; D009866:Oogenesis / Q000502:physiology; D011817:Rabbits; D059467:Transcriptome / Q000502:physiology*