A retrospective model of oocyte competence: global mRNA and housekeeping transcripts are not associated with in vitro developmental outcome
Biase, Fernando Henrique; Martelli, Lúcia; Merighe, Giovana Krempel Fonseca; Biase, Weruska Karyna Freitas Santos; Miranda, Moyses; Smith, Lawrence Charles; Meirelles, Flávio Vieira; Biase Fernando Henrique; USP-FZEA – Departamento de Ciências Básicas, Rua Duque de Caxias Norte, 225, Pirassununga–SPBrazil.; Faculdade de Zootecnia e Engenharia de Alimentos–Universidade de São Paulo; Faculdade de Medicina de Ribeirão Preto–Universidade de São Paulo; Martelli Lúcia; Faculdade de Medicina de Ribeirão Preto–Universidade de São Paulo; Merighe Giovana Krempel Fonseca; Faculdade de Zootecnia e Engenharia de Alimentos–Universidade de São Paulo; Biase Weruska Karyna Freitas Santos; Faculdade de Zootecnia e Engenharia de Alimentos–Universidade de São Paulo; Miranda Moyses; Faculdade de Zootecnia e Engenharia de Alimentos–Universidade de São Paulo; Smith Lawrence Charles; Faculdade de Zootecnia e Engenharia de Alimentos–Universidade de São Paulo; Université de Montréal; Meirelles Flávio Vieira; USP-FZEA – Departamento de Ciências Básicas, Rua Duque de Caxias Norte, 225, Pirassununga–SPBrazil.; Faculdade de Zootecnia e Engenharia de Alimentos–Universidade de São Paulo
Журнал:
Zygote
Дата:
2009
Аннотация:
SummaryOocyte developmental competence depends on maternal stores that support development throughout a transcriptionally silent period during early embryogenesis. Previous attempts to investigate transcripts associated with oocyte competence have relied on prospective models, which are mostly based on morphological criteria. Using a retrospective model, we quantitatively compared mRNA among oocytes with different embryo development competence. A cytoplasm biopsy was removed from in vitro matured oocytes to perform comparative analysis of amounts of global polyadenylated (polyA) mRNA and housekeeping gene transcripts. After parthenogenetic activation of biopsied oocytes, presumptive zygotes were cultured individually in vitro and oocytes were classified according to embryo development: (i) blocked before the 8-cell stage; (ii) blocked between the 8-cell and morulae stages; or (iii) developed to the blastocyst stage. Sham-manipulated controls confirmed that biopsies did not alter development outcome. Total polyA mRNA amounts correlate with oocyte diameter but not with the ability to develop to the 8-cell and blastocyst stages. The last was also confirmed by relative quantification of GAPDH, H2A and Hprt1 transcripts. In conclusion, we describe a novel retrospective model to identify putative markers of development competence in single oocytes and demonstrate that global mRNA amounts at the metaphase II stage do not correlate with embryo development in vitro.
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