| The insect juvenile hormone III(JH III),is a class of terpenes,which can maintain the characters of insect larvae and promote the development of adult gonadal glands.Its main function includes two aspects: first is to keep the larval state in larvae stage;second is,in the adult stage,to promote the development of ovary and oocyte.JH III exist widely in many kinds of insects,and is one of the common hormones in insect endocrine regulation.Recently,in the study of perinereis aibuhitensis,many scholars have found that brain hormone secreted from perinereis aibuhitensis has the same function of juvenile hormone,which plays a decisive role on germ cells in its early stage.Through feeding the cultured perinereis aibuhitensis with fodder containing different concentration of juvenile hormone III,this experiment proved the influence of juvenile hormone III on the development of oocyte by observing the oocyte diameter changes,oocyte development and histology of female adult somatic yolk protein expression of Nereis in certain breeding circle.In this experiment,five different feed concentration levels have been set up(1mg/kg,5mg/kg,25mg/kg,50mg/kg,100mg/kg),and changes in the diameter of egg cell and the number of the heteronereis variation in breeding circle of 20,40,and 90 days have been recorded which contributes to the preliminary research of the juvenile hormone III.Then,in order to further study the influence of juvenile hormone III and other kinds of hormone,and provide base data to the proceeding of the development of cultured oocyte and the artificial breeding production,a list of study have been done and the result are as follow.1.JH ? of 1mg/kg barely has effect on the perinereis aibuhitensis,and in the concentration of 5mg/kg,25mg/kg,50mg/kg,100mg/kg,juvenile hormone III was found has obviously promotion on oocyte maturation of adult worms,and has hit the peak in the 20 thdays of the breeding circle.This influence will increase with a high concentration,and concentration of 100mg/kg has the best result.But when the feeding period reached 40 d,eggs in those groups that with the concentration of 50,100mg/kg plateaued when entered the mature growth phenomenon.Analysis show that high concentration of juvenile hormone III can inhibit the body from entering the next stage of growth.However,the mechanism and pathway is not clear,thus need further study.The experimental results show that different concentration of juvenile hormone III can promote germ cell development in different degree,and this effect is most obvious in 20 thday,which indicated that there is a sensitive cycle and range in the course of juvenile hormone III.According to the different concentration of insect juvenile hormone III feed under Perinereis tissue,intestinal epithelial cells and lobworm oogenesis observation,determination of effects of juvenile hormone on Nereis body tissues.Found in the artificial breeding cycle 40 d,perinereis aibuhitensis intestinal muscle layer thickness,the number of folds and the wrinkle wall thickness had no significant difference with control group,the thickness of coelomic epithelial cells and the control group with the change of time showed normal levels,oogenesis did not cause cell damage.It can determine the juvenile hormone III in Nereis oocytes,is a kind of hormone regulation of germ cells development.2.Through observing the sections of intestine,epithele and egg of perinereis aibuhitensis cultivated under different concentration of juvenile hormone III,the influence juvenile hormone III may have on the tissue section of perinereis aibuhitensis was measured.Results show that in 40-days breeding circle,the thickness of intestinal muscle and wall and the number of intestinal wall has marginally difference between experimental groups and control groups.All the three features were in normal condition and there was no damage in eggs in the whole development process.Therefore,it can determine that the juvenile hormone III is a sound hormone in the regulation of germ cells development.3.It was found in ELISA experiment that the expression of yolk protein was significantly promoted in 10 th day of feeding.In addition to 1mg/kg feeding treatment group and control group,yolk protein expression of treatment groups with different concentration(5 ? 25 ? 50 ? 100 mg/kg)showed a significant difference compared to the control group,and appeared a progressive increase trend,among which the expression of 100 mg/kg feeding group of yolk protein was the highest,there was significant difference(P < 0.01).However in 20 thday,the expression of 50 and 100 mg/kg feeding treatment groups were lower than the control group,and there was significant difference(P < 0.05),in 40 thday,the expression of 5,25,50,100 mg/kg feeding treatment groups were lower than the control group,the expression increase with decreasing concentration.Combined with the development degree and egg cell diameter of egg cell,it is easy to notice that juvenile hormone III has no obvious effect on in the later period of the development of germ cells and has no inhibition on subsequent metamorphosis.experimental results show that juvenile hormone III has significant influence on the expression of eggs yellow protein in a certain concentration range and breeding cycle.4.Through the calculation of heteronereis in of each treatment group and control group the number in 90 th day,the effect has on the metamorphosis of reproductive has been measured.It has been found that juvenile hormone III of 50,100mg/kg feeding group of was significantly inhibited the form of heteronereis,and the concentration of 25mg/kg,on the contrary,can promote the formation,and the concentration of 1,5mg/kg has marginally effect in the process. |
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