| The nuclear receptor (NR) as ligand-dependent transcription factor belongs to a very complex protein super-family, Which regulate gene expression after ligand binding in the nucleus. One of the receptors’ specific physiological ligand has yet to be identified, which known as orphan nuclear receptor. Estrogen-related receptor (ERR) is the first discovered the orphan nuclear receptor, share high homology with estrogen receptor (ER). The main performance of the biological function of ERR is involved in estrogen signaling pathway in different ways, share common target genes with ER in the bone tissue and breast tissue. ERR is also involved in the regulation of the glycolytic pathway in Drosophila, plays an important role in the regulation of reproductive development and metabolism. Ecdysteroid receptor (EcR) is a nuclear receptor belongs to the nuclear receptor subfamily 1(NR1). The physiological process of insect’s growth and development,such as molting and metamorphosis are strictly regulated by ecdysone. EcR as the target of ecdysone plays a very important role for starting cascade reaction in the insect metamorphosis, molting and reproduction, especialy in regulate the insect growth and reproduction process,.Polyrhachis vicina Roger belong to Formicida, Polyrhachis Smith insect, which is a kind of typical social insects of the gregarious and can be used for both food and medicine with certain economic significance.In this study, we use Polyrhachis vicina Roger as the experimental subject, observe the development process and life history. Through RNA interference technology, depress ERR gene expression in vivo of Polyrhachis vicina Roger, then detection the expression of the PvERR and PvERR protein in different developmental stages after RNAi with Western blot and immunohistochemistry detection technology. Speculation the effect of PvERR on reproductive development and differentiation grade of Polyrhachis vicina Roger, and speculation the correlation of function between PvERR and PvEcR. The main research results are as follows:1、P. vicina breedin one generation takes 40-60 days, which egg development time was (24.5±3.5) days, larval development period was (25±5.5) days, pupa development period was (20.5±5.5) days. According to the measured datas and Dyar’s rule, P. vicina larvae stage are divided into four instars, the first instar undergo (4.5±1.5) days, second instar undergo (5.5±1.5)days, the third instar undergo(7.0±1.0)days, and fourth instar is covered (8.0±1.5) days. P. vicina breeding one or two generation during a year. The adult workers exists in the nest throughout the year. Males eclosion from August to November, and will existed in the nest until the following May, which lifetime was 6-9 months. Females eclosion only in October, dealation became Queen after mating, and exists in the nest throughout the year.2、The expression of PvERR in protein levels at different developmental stages. The expression from egg to third instar was relatively low, but the expression of PvERR protein was gradually increased from the beginning of the fourth instar, until the adults reach the highest. While in the three grade of adult, the highest expression is female, the second is worker, and the male is the least. After RNAi, the expression of PvERR is significantly decreased in 4 instar larvae, and significantly decreased in the pupal. The expression of PvERR in three grades of adults has been detected, while the female decreased significantly, followed by the worker, and finally the male. Therefore, we speculate that PvERR may be involved in the metabolic pathway, and plays an important role in regulatory of growth and development process. While the different expression of ERR in different grade of adult shows that the gene may be related to the caste differentiation and social division of ant. Immunohistochemical results shows that PvERR has a different degree of positive expression in different head of three grade of Polyrhachis vicina adults. The mushroom body and spherical cells has strong positive reaction in the head of worker and female. While it has very strong positive reaction in male’s optic lobe. Afrte RNAi, the positive expression of PvERR decreased significantly, in mushroom body and spherical cells of female and worker, and also decreased significantly in male’s optic lobe. So we can speculate about this, PvERR play an important role in the construction of the nervous system, especially in the male’s visual nervous system.3、Compared with the control group, we found that the expression of PvEcR has decreased significantly in fourth instar larvae and pupal stage after RNAi of PvERR. Among the three grades of adults, the expression of female’s head has significant difference between control group and experience group after RNAi, the worker head and abdomen, and the abdomen of female has a certain degree of decreased, while the differences of males is not obvious. Immunohistochemical detection the expression of PvEcR protein after RNAi of PvERR. As the result, the positive expression of PvEcR has decreased in the mushroom body and spherical cell in the head of the worker, the positive expression of the mushroom body and the spherical cells of females also have a certain degree of decreased. The same decreased also shows in male’s brain, while the optic lobe decreased significantly. So we speculate that PvERR and PvEcR are involved in lipid synthesis metabolism pathway of P.vicina larvae.This study observation and research the life cycle of P.vicina for the very first time, laid the foundation for the following study such as study on the cellular level and molecular level of P.vicina. Research on the localization and quantitative of ERR gene at the protein level of Formicidae insect for the first time, enrich the research content of ERR gene in insect. For the first time study on the function correlation of PvERR and PvEcR, providing the basis to explore its role in the process of reproductive development of P.vicina. And try to use P.vicina as model animal, chart a new path in study on the related gene of animal reproductive development and behavior. |
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