Cellular apoptosis susceptibility gene messenger ribonucleic acid in theovary of red seabream: molecular cloning and correlation with acquisitionof oocyte maturational competence

摘要

This study has used differential display-PCR, to amplify genes transcribed during oocyte maturation induced by human chorionic gonadotropin (hCG). A cDNA expressed in time of acquisition of oocyte maturation of red seabream (Pagrus major) by treatment of hCG was amplified and cloned. A full-length cDNA of the cellular apoptosis susceptibility gene for red seabream was isolated using differential display-PCR and 5' RACE. This cDNA clone contained 3560 nucleotides including the open reading frame (ORF) that encoded a protein of 971 amino acids. The deduced amino acid sequence shows 87% identity and 97% similarity to human cellular apoptosis susceptibility gene. Consensus sequences consistent with sites for phosphorylation by protein kinase C was identified. Red seabream cellular apoptosis susceptibility gene (CAS) transcript level increased between 9 and 12 h after the incubation with hCG. Red seabream CAS mRNA transcript level was increased by treatment of GtH-II (300 ng ml(-1)). Moreover, in vivo, red seabream CAS mRNA was strongly expressed after, but not before the acquisition of oocyte maturational competence. These results suggest that an obligatory element of the hCG induction of maturational competence is the de novo synthesis of red seabream, Pagrus major CAS (PmCAS).