Exprassion Pattern And Function Of MyD88 At Gram-bacteria Challenged And Different Development Stages Of Artemia Sinica

Artemia sinica belongs to Phylum Arthropoda, Class Crustacea, Subclass Branchiopoda, Order Anostaca, Family Artemiidae and Genus Artemia. Artemia lives in the coastal and inland salt water.It is a very important economical diet.Because of its development is short and it is resistant to drought, temperature, pressure and other adverse environments made that it has been extensively studied as an important laboratory animals,especially in the experimental material of innate immunity.Invertebrates do not have the adptive immune, only the innate immune. In the innate immune response, Toll pathway is required to induce antimicrobial peptide expression and to defence anti-fungal and anti-Gram-positive bacteria. MyD88 is a critical adapter protein in Toll signaling pathways. When bodies are affected, Spatzle activates Toll,then transportes signals to MyD88, after a series of signaling cascades, MyD88 triggere immune response. In addition, MyD88 is found have a certain effection on the dorsal-ventral axis formation during the embryonic development in Drosophila. So the research on the expression of MyD88 during embryonic development and immune mechanisms in Artemia has a very important significance. In this study A. sinica were used as materials to study the experission at different development stages and role of immune response in Gram-bacteria Challenged in A. sinica.The part sequnce of Artenia sinica MyD88 gene fragmtent was obtained by PCR technology in A.sinica. We also obtain the 1555bp full length of MyD88 cDNA by RACE technology.Its molecular analysis reveale that the sequence includes a length of 1182bp open reading frame and encodes 393 amino acids. The annlysis of the protein strucrure and amino reveal that it contains death domain in N terminal, the boxl and box2 motif of TIR domain in the C terminal.The whole of immunohistochemical technique have found that MyD88 mainly express in Sinica's head, chest.it suggest that it may be related to the formation of immune factors. Real-time quantitative PCR technology researches the expression of MyD88 in the different periods of embryonic development of A. sinica.The result shows that its high expression is in the Oh stage and 5h stage during the embryonic development of A. sinica. So we can speculate that MyD88 may be a maternal gene to regulate the expression of immune-related genes and embryonic development genes. After Gram-positive bacteria stimulation, the expression of MyD88 increased.We can see it playes an important role in resisting to Gram-positive bacteria infection. After the stimulation of Low concentration of Gram-negative bacteria, the expression of MyD88 isn't much changed. After the stimulation of high concentration of Gram-negative bacteria infection, the expression of MyD88 increased.lt reveales that MyD88 play a role in resisting to Gram-negative bacteria.