Study On The Regulatory Function Of Hsp90 Gene And ERR Gene On Growth And Development

Heat Shock Proteins(HSPs) belong to the most important class of proteins for organisms to adapt to the environment.The expression of HSPs will be induced or up-regulation when organisms are stimulated by external environmental condition, such as hypoxia,physical damage,ultraviolet,etc. HSPs are found in all virtually living organisms,but Archaea. HSP90may be one of the most essential HSPs, many reseachers are interested in it. Now,most sdudy demonsrrate that HSP90is vital to insect development, in tribolium castaneum,the development of compound eyes and pupation are affacted by the RNA interference of hsp90gene to last-instar larva. In drosophila melanogaster, HSP90may participate in20-hydroxyecdysone signaling pathways,and HSP90is indispensible to the activation of ecdysone receptor.Estrogen-related receptor(ERR) belongs to nuclear receptor superfamily, as the first discovery of orphan nuclear receptor,there are3types,ERRα,ERRβ,ERRγ. ERRα and ERRγ expression status of mammals can be diagnosed as physical characteristics of certain tumors, especially ERRα has now been identified as one of the symbols of their breast cancer. ERR can participate in the estrogen-mediated signaling pathways by different ways, ERR and estrogen receptor (estrogen receptor, ER) has the same target gene in bone tissue and breast tissue. ERR studies in insects is still relatively little,in Drosophila melanogaster,ERR was found to be involved in the regulation of glycolysis, and also plays an important role in its process of growth and metabolic regulation.In this paper,a study about hsp90gene of Polyrhachis vicina and ERR gene of Teleogryllus emma.respectively has been investigated.Polyrhachis vicina belong to Polyrhachis of social insect life, mainly in the tropical rain forest in Xishuangbanna, Yunnan in our country. Because of its special growth environment,they have a good therapeutic effect on liver disease, diabetes, rheumatism, etc. Polyrhachis vicina have strict grade of differentiation,it is good material to study the individual development of insect. In this experiment, we take the ant as material,hsp90gene was detected in the head of Polyrhachis vicina by situ hybridization,and interfere hsp90gene of double-stranded RNA and real-time quantiative RT-PCR techniques.The expression of EcR and USP was detected when hsp90gene was interfered,then the correlation of these three genes was speculated.The main results are offered as follows: (1) hsp90gene expression was positioned in the three grades of the head by in situ hybridization. Results show that the gene is expressed in all the three grades, but the expression level is low. Compared with the male and worker,the expression level of hsp90gene in the head of female is relatively higher,which proved hsp90gene may take an important role in female.The expression of the gene has no apparent difference in the brain of all grades,it suggusts that HSP90may have some relationship,but no directrelationship with special behavior of insects.(2)A fragment of hsp90gene was cloned, then add T7promoter to its5-region,dsRNA is synthesized by this fragment. Polyrhachis vicina is fed by dmixture of dsRNA and crystal sugar or other food.After14days,the expression of hsp90gene is detected by RT-PCR. The result show that hsp90gene expression is down-regulated,in female52.45%,in male71.12%,in worker44.45%.The detection of the expression of USP gene indicate that USP is down-regulated after hsp90is interfered,but EcR has no significant change.This result suggests that the expression of hsp90gene and USP gene may have close relationship.T. emma (Teleogryllus emma) belongs to Teleogryllus of Gryllidae, they are widely distributed in various provinces and cities in China. This species possesses large size, generally length18-26mm,brown or dark brown body,most like live near the grassland and rice field, head is large, like a round ball.There is a special structure in the head of this insect.The full-length cDNA of T. emma ERR and EcR has been obtained by Doctor He Hui, the accession numbers of GenBank database are FJ770332and HQ131915. Injection method is used in T. emma..Two pairs of primers is designed, then using product compound dsRNA.The results of this study are offered as follow:(1)two fragments is obtained,Seq1and Seq2.Their length are632bp and528bp.Using the fragments to synthesis appropriate dsRNA.dsRNA is applied to RNAi of ERR gene.The result shows that Seq1is better than Seq2.(2)ERR gene is interfered by Seq1both in female and male,the result of RT-PCR demonstrates that the expression of ERR gene is reduced.In female it drops down50.2%,and55.3%in male.(3)When ERR gene is interfered in this insect,the expression of EcR gene is detected.It shows that EcR gene is reduced75.99%in female,but increased17.57%in male.This result suggests that the expression of ERR and EcR may have the correlation in gene function,and this relationship mayvary with insect sex. The study provides a preliminary basis for the further study of hsp90gene and ERR gene in insect.