CLONING AND EXPRESSION ANALYSIS OF THE REGULATORY SUBUNIT B GENE OF PP2A IN THE MUD CRAB SCYLLA PARAMAMOSAIN
拟穴青蟹（Scylla paramamosain）PP2A调节亚基B的基因克隆与表达分析

In this paper, the regulatory subunit B geneof PP2A (PP2A-B) was isolated from the mud crab, Scylla paramamosain using RT-PCR and RACE methods. The obtained full-length cDNA of PP2A-B was 2040bp with an open reading frame of 1332bp encoding a putative peptide of 443 amino acid. By alignment, the amino acid sequence of S. paramamosain PP2A-B showed high homology with those of some other animals. It suggested PP2A-B was highly conservative. Real-time PCR showed that the PP2A-B gene was expressed in various tissues, and highly expressed in brain, ovary and gill. The PP2A-B mRNA expression during ovarian development indicated that the expression of PP2A-B was obviously high at undeveloped stage and decreased gradually from stage I (undeveloped stage) to stage V (ripe stage). We hypothesized that PP2A-B may exist in the form of PP2A holoenzyme in ovary and play a suppressive role on the ovarian development of the mud crab.