Steroid-induced oocyte maturation in Indian shad Tenualosa ilisha (Hamilton, 1822) is dependent on phosphatidylinositol 3 kinase but not MAP kinase activation

作者：Pramanick Kousik; Kundu Sourav; Paul Sudipta; Mallick Buddhadev; Moulik Sujata Roy; Pal Puja; Mukherjee Dilip^*

来源：Molecular and Cellular Endocrinology, 2014, 390(1-2): 26-33.

DOI：10.1016/j.mce.2014.04.002

• 17,20 beta-P
• Oocyte maturation
• PI3 kinase
• MAP kinase
• cdc2 kinase
• Tenulosa ilisha

Fully grown fish and amphibian oocytes exposed to a maturation-inducing steroid (MIS) activates multiple signal transduction pathways, leading to formation and activation of maturation-promoting factor (MPF) and induction of germinal vesicle breakdown (GVBD). The present study was to investigate if phosphatidylinositol 3 kinase (PI3 kinase) and mitogen-activated protein kinase (MAP kinase) activation are required for naturally occurring MIS,17 alpha,20 beta-dihydroxy-4-pregnen-3-one (17,20 beta-P)-induced cdc2 activation and oocyte maturation (OM) in Tenualosa ilisha. We observed that17,20 beta-P-induced OM was significantly inhibited by PI3 kinase inhibitors Wortmannin and LY29400. 17,20 beta-P was shown to activate PI3 kinase maximally at 90 min and cdc2 kinase at 16 h of treatment. Relative involvement of PI3 kinase, MAP kinase and cdc2 kinase in 17,20 beta-P-induced OM was examined. MAP kinase was rapidly phosphorylated and activated (60-120 min) after MIS treatment and this response preceded the activation of cdc2 kinase by several hours. A selective inhibitor of MAP kinase (MEK), PD98059, sufficiently blocked the phosphorylation and activation of MAP kinase. Inhibition of MAP kinase activity using PD98059 however, had no effect on MIS-induced cdc2 kinase activation and GVBD. These results demonstrate that activation of the PI3 kinase is required for 17,20 beta-P-induced cdc2 kinase activation and OM in T. ilisha. MAP kinase although was activated in response to 17,20 beta-P and PI3 kinase activation, it is not necessary for cdc2 activation and OM in this species.

• 出版日期2014-6-5