Expression Of API5 And Function Study In Early Embryonic Developmental Of Artemia Sinica

Artemia sinica belongs to Phylum Arthropoda, Crustacea, Branchiopoda, Order Anostraca, Family Artemiidae and Genus Artemia. Artemia sinica lives in the high-salt salt lakes and salterns where mainly exsists in Inner Mongolia, Tibet, Xinjiang, Qinghai and Shanxi. It is such a good biological diet that it is applied to breeding industry.Apoptosis inhibitor5(API5)plays a vital role in the embryonic development stages in Artemia sinica. It is an apoptosis inhibitor related protein, and regulates apoptosis in the vertebrates and invertebrates. By molecule clone technique, we obtain API5 gene fragment of the length 403bp. Besides, using 3'-5'RACE technology, the full-length with 1711bp base of API5 gene cDNA is cloned. The full-length sequence is demonstrated is API5 in Artemia sinica by using Blast analysis(GenBank accession No. : JF808079).The expression of API5 gene is analyzed at the different embryonic development stages of Artemia sinica by using Real-time PCR. The experimental results showed that relative expression quantity of API5 is the highest at gastrula of Artemia sinica. The expression of API5 increased gradually during 0h～10h and decreased gradually druing 15h～40h, then increased druing 3d～7d, and last decreased at 10d. The results showed that API5 is a significantly embryonic developmental regulated gene in Artemia sinica, and it can protect embryonic development from apoptosis at diapause.The functions of API5 were studied by testing expression of the gene under stress of different temperature, salinity and gram-negative bacteria challenged. The results showed that the expression of API5 gene had remarkable change by using salinity stress, temperature and bacteria stimulation. In the different salinity, the relative expression level of the gene increased significantly (p<0.01). Under temperature stimulation, with the decreasing of temperature, expression of gene showed up-regulation. Relative expression of API5 showed down-regulation by gram-negative bacteria, while its expression level showed up-regulation by gram-positive bacteria challenged. The experimental results showed that in various environmental stress, API5 may protect embryonic development from apoptosis. The related protein amino acid sequence was analyzed by using MEGA 4.0 software in order to know meaning of these putative proteins in the biology evolutionary. The bioinformatics, evolutionary relationship and functional identification were discussed, the from these research results of API5 gene will offer a major theoretical basis for researching developmental biology and knowing diapause in Artemia sinica.