Vitellogenesis in the Red Crab, Charybdis feriatus: Contributions from Small Vitellogenin Transcripts (CfVg) and Farnesoic Acid Stimulation of CfVg Expression
Abstract: During reproductive maturation of the female red crab, Charybdis feriatus, the oocytes rapidly accumulate 110- and 78-kDa major polypeptides. Although the hepatopancreas expresses a high level of vitellogenin (CfVg) mRNA, tissue proteins and secreted proteins of the hepatopancreas consist of only small polypeptides. In addition to the 8.0-kb transcripts, many smaller mRNAs specific to the CfVg gene can be detected. These results suggest that the hepatopancreas also produces smaller CfVg transcripts for small CfVg subunits. Using an RT-PCR cloning approach, a population of the small cDNA clones were isolated. Determining the DNA sequence of these clones revealed that these transcripts were most likely the result of alternative splicing and/or alternative expression of the CfVg gene. In vitro treatment of the hepatopancreas fragments with low levels of farnesoic acid stimulated the expression of CfVg.
vitellogenesis crab vitellogenin farnesoic acid reproduction hepatopancreas alternative transcripts crustaceans