Identification And Characterization Of Genes In Artemia And The Roles In The Diapause Embryo Formation

The brine shrimp Artemia parthenogenetica is a primitive and genius Crustacean. To withstand the extreme environments, Artemia has evolved a special reproductive mode. In ovoviviparous pathway, it gives birth to swimming nauplii, and in the oviparous pathway, it releases diapause cysts, which can remain in a dormat state for many years, and only resume development with the approach of suitable conditions. During the development of encysted embryos of Artemia, drastic events would occur inside the embryo, including deposited energy mobilization, cellular differentiation, macromolecular synthesisand morphological changing, but no cell division occurs before emergence. However, still little is known of the unusul mechanisms of Artemia diapause and development.We selected4genes, glutaminase(Ar-GLS), Ste20-like kinase(Ar-SLK), prohibitin2(Ar-PHB2)and autophagy related gene5(Ar-Atg5), which are related to development of Artemia-encysted embryos. Through the method of RT-PCR, we isolated fragments of Ar-GLS, Ar-SLK and Ar-PHB2, and Ar-ATG5, respectively. Furthermore, we obtained the complete cDNA sequences of the first three genes, and identified their mRNA levels during the developmental stages. After analysis of Ar-GLS, we built E. coli expression system for the specific anti-ArGLS. By the inhititor DON, the degradation of vitellogenin in the naulius slowed down. Furthermore, the phosphor-AMPK was in a high level. In other hand, exposure of nauplius larvae, produced by adults with Ar-SLK RNAi, to heat shock, a pH, UV irradiation and anoxia stresses, the survival rates were lower than those of control larvae from females injucted with GFP dsRNA. Our finding lay the foundation for future research of mechanism in Artemia diapause and development.