Expression Pattern Of As-NGR Gene During Embryonic Development And Under Salinity, Temperature,20-hydroxyecdysone Stress Of Artemia Sinica

Artemia sinica is a kind of small crustacean with a strong adaption to environment.Theycan survive in high salt waters. Due to its unique advantages in scientific research, A. sinicahave been an important model organism for the research of molecular biology, genetics,developmental biology and other subjects.In recent years, the function of neuropeptides and their receptors in regulating growth,development, reproduction, movement and other physiological in crustacean have been paidmore attention but no one had published on the research of neuropeptides and their receptorsin A. sinica.In this paper, RACE technology was used to obtain the full-length cDNA sequence ofthe As-NGR gene from A. sinica for the first time. Bioinformatic was been used to analyse theputative amino acids of gene. In situ hybridization was used to research the expressionposition of As-NGR in different stage during embryonic development. Real-time PCR wasperformed to research the expression level of As-NGR during the embryonic development ofA. sinica and in response to salinity, temperature and20-Hydroxyecdysone stresses.The results show that the full-length1610bp cDNA sequence of the As-NGR genecontained an open reading frame of1527bp, an5’-untranslated regions （UTR） of59bp andan3’-UTR of24bp.Bioinformatic analysis show that the putative As-NGR protein contained508amino acids with a seven-transmembrane G-protein-coupled receptor family of rhodopsin（7TM₁） motif and a serpentine receptor w （7TM_GPCR_Srw）.It is a hydrophobin whichacross the cell membrane seven times and has a calculated molecular mass of60.8Kd, a pI of5.73.As-NGR was broadly distributed in the whole body and all stages of embryonicdevelopment and the relative expression levels of As-NGR gene in different embryonicdevelopment stages was also diverse. The expression level of As-NGR was lower before15hand then gradually increase, especially for5d and7d,were much higher other stages. Theexpression level of As-NGR was decrease with the increasing of salinity and all below thenormal level（28‰）. The expression level of As-NGR is decrease with the reduction oftemperature and all below the normal level（4℃）. The transcript level of As-NGR has anobvious up-regulated when20-Hydroxyecdysone induced treatment for1h and then declinerapidly. Although these informations cannot help us determine the ligand of As-NGR, they alsoimply that As-NGR may not be the response factors of low temperature and high salinity, butplay an important role in the early stages of molting. Researching on neuropeptide receptorsmay have a certain theoretical significance for understangding the effection ofneuroregulation, and helpful to research the processes of neuroregulation in A. sinica.