PP2A-Aα/β在金鱼及斑马鱼发育中的分化表达模式

摘要

以金鱼和斑马鱼为研究对象,运用RT-PCR和Western Blot技术分析蛋白磷酸酶2A(PP2A)结构亚基A(PP2A-Aα/β)在金鱼、斑马鱼成体9种组织和12个发育时期胚胎中mRNA和蛋白水平的表达情况,得到其分化表达模式为:(1)在mRNA水平上,PP2A-Aα/β在金鱼、斑马鱼9种组织中具有较强表达:种属差异性和组织差异性均较大;结构亚基A的两亚型Aα和Aβ的表达存在差异.(2)在蛋白水平上,PP2A-Aα/β在金鱼、斑马鱼9种组织中均有表达;种属差异性不大但出现明显的组织差异性.(3) PP2A-Aα/βmRNA在金鱼和斑马鱼卵裂期到囊胚期胚胎中大量存在,PP2A-Aα mRNA在金鱼眼色素期量剧增推测其对金鱼眼色素的形成至关重要.(4)PP2A-Aα/β基因在金鱼、斑马鱼12个发育时期胚胎中均有较高水平的蛋白存在,提示其为维持胚胎的正常发育发挥重要作用.%Protein phosphatase-2A (PP2A) is a major serine/threonine phosphatase and accounts for more than 50％ serine/threonine phosphatase activity in eukaryotes. The holoenzyme of PP2A consists of the scaffold A subunit, the catalytic C subunit and the regulatory B subunit. The scaffold subunit, PP2A-Aα or PP2A-Aβ, provides a platform for both C and B subunits to bind, thus playing a crucial role in providing specific PP2A activity. To explore the possible functions of PP2A in the development of lower vertebrates, we analyzed the differential mRNA and protein expression patterns of the scaffold subunit A for PP2A using RT-PCR and western blot analysis on 9 tissues and 12 developmental stages of goldfish and zebra fish embryos. Our study demonstrated the following results: (1) PP2A-Aα/β mRNAs were differentially expressed in various tissues of the goldfish and zebra fish; within the same tissues of the two types offish, PP2A-Aα/β mRNAs had the different expression patterns. (2) PP2A-Aα/β proteins were differentially expressed in various tissues of the goldfish and zebra fish; within the same tissues of the two types of fish, PP2A-Aα/β subunits had the same protein expression pattern. (3) PP2A-Aα/β mRNAs abounded in the stages of two-cell, multiple-cell, blastula of goldfish and zebra fish embryos. Especially, PP2A-Aα mRNA had a distinct increase in the goldfish eye pigmentation stage embryo, suggesting it was essential to the formation of the goldfish eye pigmentation. (4) In the 12 developmental stages of embryos, PP2A-Aα/β proteins had the high expression level, suggesting that PP2A-Aα/β appeared to play a very important role during goldfish and zebra fish development. These results suggested that PP2A-Aα/β might play a very important role during embryos development and also in adult tissue homeostasis of gold fish and zebra fish.