Hormonally regulated expression and alternative splicing of kit ligand may regulate kit-induced inhibition of meiosis in rat oocytes.
Dev Biol
; 184(2): 333-42, 1997 Apr 15.
Article
em En
| MEDLINE
| ID: mdl-9133439
ABSTRACT
Mutations in the genes encoding the Kit tyrosine kinase receptor or kit ligand (KL) cause numerous phenotypic defects, including sterility. In the postnatal ovary, Kit is expressed on the oocyte surface and KL is produced by the surrounding granulosa cells, but its function in these cells is still unknown. The purpose of this study was to determine the role KL/Kit interactions play in the regulation of oocyte meiosis. Here, we demonstrate that meiotically arrested rat oocytes that are microinjected with Kit antisense oligonucleotides have decreased Kit expression. This decreased expression is associated with an increased ability of these oocytes to resume meiosis compared with those microinjected with missense oligonucleotides or buffer alone. In addition, oocytes cultured in the presence of KL were delayed in their resumption of meiosis, but KL could not enhance the meiosis inhibitory effects of dibutyryl cAMP, suggesting that KL operates through a mechanism that is independent of cAMP. Human chorionic gonadotropin-induced meiotic resumption in oocytes was accompanied by a shift in follicular granulosa cell KL expression from membrane-bound to soluble forms and a loss of expression of both forms of KL in cumulus cells. Thus, KL-activated Kit inhibits meiotic progression, and the in vivo luteinizing hormone-stimulated resumption of meiosis may negate Kit activity by a localized decrease in KL expression and by altering the form of KL produced within the follicle.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oócitos
/
Hormônio Luteinizante
/
Regulação da Expressão Gênica
/
Processamento Alternativo
/
Fator de Células-Tronco
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Proteínas Proto-Oncogênicas c-kit
/
Meiose
Limite:
Animals
Idioma:
En
Revista:
Dev Biol
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Canadá