Expressions In Different Development Stages And Different Concentrations Of Gram-positive Bacteria Challenged Of Sp Tzle Gene Of Artemia Sinica

Artemia belongs to Crustacea, Branchiopoda, Anostacea, Artemidae, Artemia. It is widely distributed in salt lake and inner and coasting saltworks.Sp(?)tzle gene which is relative to the development of embryo codes a NGF-like protein. In the course of dorsal ventral axis differentiation, Sp(?)tzle is activated by a protease coded by easter gene and then binding to the Toll receptor in ventral axis of oocyte which starts the ventral axis development. Besides, Toll pathway is main immune response in fungi and gram positive bacteria infection of invertebrate, but because the Toll receptor could not be directly activated by pathogenic microorganism, so Sp(?)tzle mediated this signal pathway as an important receptor out of membrane. pepfidoglycan -recognition proteins as a pattern recognition receptor recognize pathogenic microorganism and lead to the hydrolysis of SPE ,this course will activated Sp(?)tzle and start the Toll pathway. In this paper, we designed a pair of primers based on the sequence of A.franciscana in Genbank. PCR was performed using the total cDNA of Artemia sinica and we get a 297bp sequence fragment. Blastn, open reading finder and ClustalX 1.83 analysis indicated that the fragment is a part of the full length cDNA of Sp(?)tzle gene in Artemia sinica. Real time PCR primers were designed by this partial sequence. The expression of Sp(?)tzle has been researched in diverse stages during embryonic development in Artemia by several molecular biology methods including real-time PCR analysis and Immunohistochemistry assays. The result shows that Sp(?)tzle gene could be detected in every different development stages and mainly expressed in head, thorax and ventral in early stages and on the surface of the alimentary canal and chap in later stages. The relative expression of Sp(?)tzle genes at the development of A. sinica showed a decreasing and then rising trend. While challenged by rising concentration of gram positive bacteria, the expression of Sp(?)tzle genes is also increasing. To sum up, Sp(?)tzle gene is not only participate the dorsal ventral axis development but also play an important role in the innate immune system in early embryo development of Artemia sinica.