Characterisation of the cellular and molecular responses of ovine oocytes and their supporting somatic cells to pre-ovulatory levels of LH and FSH during in vitro maturation.
Reproduction
; 144(2): 195-207, 2012 Aug.
Article
em En
| MEDLINE
| ID: mdl-22718856
ABSTRACT
The response of Graafian follicles to pre-ovulatory surge levels of FSH and LH in vivo triggers the terminal differentiation of granulosa cells and oocyte maturation. In polyovular species, the LH-driven signalling uses the epidermal growth factor (EGF)-like ligands AREG, EREG and BTC to promote oocyte maturation and cumulus expansion. This experimental series used a physiologically relevant ovine in vitro maturation (IVM) system to evaluate the impact of exposure to pre-ovulatory levels (100â ng/ml) of LH and FSH on ovine cumulus cell expression of EGF-like ligands in vitro. The serum-free sheep IVM system supported high levels (91.4%) of gonadotrophin-induced maturation of cumulus-enclosed oocytes and embryo development to the blastocyst stage (34.5%). Results were equivalent to a serum-based IVM system (85.1% IVM, 25.8% blastocyst rate; P>0.05) but were significantly different (P<0.05) to serum-free medium without gonadotrophins (69.5% IVM; 8.0% blastocyst rate). Ovine BTC was cloned and sequenced. Gonadotrophin-induced AREG, EREG, BTC and EGFR expressions were quantified in cumulus and mural granulosa cells during IVM. A rapid induction of AREG expression was apparent in both cell types within 30â min of gonadotrophin exposure in vitro. LHCGR (LHR) was detected in mural cells and FSHR in both cumulus and mural granulosa cells. The data confirm the involvement of AREG and EGFR during gonadotrophin-induced cumulus expansion, oocyte maturation and the acquisition of developmental competence by sheep oocytes matured in vitro.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oócitos
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Hormônio Luteinizante
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Células do Cúmulo
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Técnicas de Maturação in Vitro de Oócitos
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Hormônio Foliculoestimulante
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Células da Granulosa
Limite:
Animals
Idioma:
En
Revista:
Reproduction
Assunto da revista:
MEDICINA REPRODUTIVA
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Reino Unido