Cloning, Bioinformatic Analysis And Differential Expression After Stimulating With Antigens Of Lampetra Japonica CD45

CD45, a kind of transmembrane glycoprotein, is widely expressed on all nucleated- hematopoietic cells. Therefore, it also called leukocyte common antigen. Due to phosphatase domains in the cytoplasm. through altering the structure of Src family protein tyrosine kinases, regulated the activity of protein tyrosine kinase. It also plays important roles in lymphocyte proliferation, activation, development, signaling pathways transduction, cell adhesion, et al. Besides, various CD45 isoforms are expressed on the surface of lymphocytes as a result of alternative splicing of some exons. These isoforms act a significant role in distinguishing different status of lymphocyte activation. Presently, there have made some progress by using the expression pattern of CD45 and its isoforms as a target to investigate immunological diseases, disease prevention, early diagnosis, therapy in mammals. However, the studies in the lower vertebrates organisms has not been studied yet.Lampetra japonica is one of the most ancient vertebrate species, considered as the transitional organism connecting the vertebrates and invertebrates. Owing to its specific position during the species evolution, Lampetra japonica is viewed as an important model animal for studying the origin, evolution of vertebrate organisms. CD45 is an important key immune factor, playing a essential role during immune system response by modulating the protein tyrosine kinases activity.Only one valuable EST sequence was found after filtering the blood cDNA library of Lampetra japonica. By comparing with other CD45 counterparts, they share a high homology in the cytoplasm domains. Then, design several primers from the conserved region, by using rapid amplification cDNA ends and RT-PCR methods, ultimately we successful cloning the whole CD45 cDNA.In order to investigate the tissues and organ related to lymphocytes-like of Lampetra japonica, we conducted the real-time PCR to examine the gene expression after the samples stimulating with specific antigens. The results revealed that in all five tissue and organ, the gene expression level was all up-regulated at different extent, especially higher in the gill, heart, blood cells after the samples stimulating with LPS, ConA. CD45 is viewed as leukocyte common antigen, only expressed on the surface of the nucleated-hematopoietic cells, the changes on the expression level indicated that these tissue and organ may closely relate with the proliferation, development of lymphocytes-like. We also use bioinformatic technologies to analyze and predict the physical and chemical properties, protein structure, gene homology, phylogenetic tree of CD45.