title: Cathepsin C transcripts are differentially expressed in the final stages of oocyte maturation in kuruma prawn Marsupenaeus japonicus.
abstract: To elucidate the molecular mechanism of oocyte maturation in the kuruma prawn (Marsupenaeus japonicus), subtractive suppression hybridization (SSH) was initially used to identify novel up-regulated genes during the final stages of oocyte maturation, followed by evaluation of the differential expression profile by macroarray and quantitative real-time RT-PCR analyses. The cathepsin C (dipeptidyl peptidase I) gene was thus found to exhibit a significantly higher expression around the onset of cortical rod (CR) formation (early CR stage, appearance of round CRs), progress to a higher mRNA level until the middle CR stage (elongation of CRs), then rapidly revert to a low expression level at the late CR stage (occurrence of germinal vesicle breakdown, GVBD), as also observed at the non-CR stage (previtellogenesis and vitellogenesis). In situ hybridization analyses revealed that the sites of the expression of cathepsin C transcripts in the ovary were distributed in both oocyte and follicle cells, particularly at the early CR stage. A full-length cDNA sequence of this stage-specific gene was subsequently determined by rapid amplification of the cDNA 3' and 5' ends (3' and 5' RACE). The deduced amino acid sequence of the 230-residue mature peptide shared 67-70% identity to the known cathepsin C in mammals. Western blot analysis showed that expression of procathepsin C protein was exclusively at CR stages. The storage site of procathepsin C protein was localized in CRs as revealed by immunohistochemical analysis. This is the first report on the full-length cDNA sequence of cathepsin C and a demonstration of its involvement in the final stages of oocyte maturation in crustacean species.
authors.affiliation: Fisheries Research Agency, National Research Institute of Aquaculture, Nansei, Mie, 516-0193, Japan.
authors.forename: Gao-Feng
authors.initials: GF
authors.lastname: Qiu
authors.forename: Keisuke
authors.initials: K
authors.lastname: Yamano
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Unuma
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D020789:Cathepsin C / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D009865:Oocytes / Q000254:growth & development* / Q000378:metabolism; D009866:Oogenesis / Q000235:genetics*; D010053:Ovary / Q000166:cytology / Q000378:metabolism; D033561:Penaeidae / Q000166:cytology* / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic / Q000235:genetics*
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D020789:Cathepsin C