Expression Pattern Of As-nurp1Gene During Embryonic Development And In Response To Stress From Artemia Sinica

Artemia sinica is widely distributed in hypersaline waters. Salinity, temperature and dissolved oxygen are important environmental factors for Artemia. The ability of Artemia to resist extreme environment stress is very strong, and the Artemia cysts can survive long-term under harsh conditions of high salinity and low temperature.NURP1(Nuclear protein1), an important stress-related protein with small molecular mass, is closely related to diapause in the development of Artemia, and the expression regulation of nurpl is complex with diverse biological functions. But little studies on the distribution and expression pattern of nurpl during embryonic development and in response to stress are investigated, more thorough studies need us to finish.In this paper, the full-length568bp cDNA sequence of the As-nurpl gene was cloned from A. sinica by RACE technology. As-nuprl cDNA contained an open reading frame of198bp, and42bp5’-and328bp3’-untranslated regions (UTR). ClustalX2.0and MEGA4.0were used to analyze the evolutionary relationships of the putative amino acids of this sequence and homologous sequences, and online services was used to analyze the amino acids sequence of As-nuprl gene putative protein. The putative NURP1protein consists of66amino acids with a basic helix-loop-helix (bHLH) motif and a bipartite nuclear localization signal (NLS), and has a calculated molecular mass of7.9kD, with a pI of10.34. The amino-acid sequences of NURP1between different species are conservative in the long process of evolutionary.In situ hybridization was performed to determine the expression position of As-nuprl during embryonic development of A. sinica. The results show that As-nuprl is widely expressed during different embryonic developmental stages of A. sinica.To determine the level of As-nurpl transcription during the embryonic development of A. sinica and in response to salinity and temperature stresses, real-time PCR analysis was performed. As-nurpl is widely expressed during different embryonic development stages of A. sinica, but the relatively quantitative expression is different. The expression of As-nurpl in the embryos collected from the ovisacs is much higher than in the embryos activated. This is followed by a dramatic down-regulation after diapause and newly up-regulated from the larval nauplius stage. The levels of As-nurpl transcripts show a dramatic down-regulation trend in the subsequent development, and then gradually up-regulated from the larval nauplius stage. The expression of As-nurpl gene gradually increased with increasing salinity and decreasing temperature in the temperature and salinity stress experiments. These findings suggest that As-nurpl is an significant stress-related gene in Artemia which may play an important role in overcoming disadvantageous environmental stresses, but also it is an important regulatory gene during embryonic development which may act as a protective factor. The research of As-nuprl expression in Artemia embryonic development and stress processes will have an important theoretical significance for study on the molecular mechanism of diapause from Artemia, and will possess an applied value for further exploitation and utilization of Artemia resources.