| This paper first reports the study on reproductive ecology of locust of Siping area in Jilin province, which belongs to frigid area, in northeast of China. The locusts are collected in fields, bred, dissected and measured in the method of immunohistochemistry and biological statistics in order to study:(l)the composition and dynamic of locust communities(Orthoptera:Acridoidea) in this area;(2)dynamic change of ovary and spermary development of dominant locusts;(3)the histological study on oogenesis of ten kinds of locusts;(4)c-kit special expression in gametogenesis of ten kinds of locusts; (5)dynamic change of c-kit special expression in gametogenesis of six kinds of the dominant locusts. The research on reproductive ecology provides some theoretical proofs for locust of biological control and utilization of resource. The research described as following:1 In 2003, from June to October we have systemically surveyed the locust resources in Siping area, Jilin province. The results show that locusts of Acridoidea in Siping area have 6 families, 22 genera and 27 species. According to locust dynamic, locusts appear on the end of June and disappear after the middle of October and the number of them arrive to the largest in the middle of August which belong to 6 families, 19 genera, 22 species. Results show O.viridulus (Linnaeus), A.cinerea Thunberg, O.infernalis Sauss, Eu.vittatus Zheng, Eu.unicolor (Ikonn.), A.heteroptera B.-Bienko and S.shirakii (I.Bol.) are dominant locusts of this area according to their percentage and dynamic. Dynamic analyses show that locusts form their order of nature and the differentia among species in appearance, life periods and death to adapt to many changes of ecological environments.2 Through breeding six kinds of dominant locusts in natural condition in Siping area of Jilin province, we have systematically studied and measured the dynamic changes of the ovary and spermary from the appearance of adult locusts to their death. Results show that the development of ovary is low in the beginning of the appearance of adult locusts but has great growth rates in the later period and keeps the high developmental level all the time. The swell of ovary volume shows a tendency ofgrowing model of a power series. The development of ovary basically conforms to five growth grades. On the contrary, the development of degree of spermary is higher in the beginning of the appearance of adult locusts, but the growth rate is lower in the later stage and shows a declining tendency after its top development. The growing volume of ovary and spermary of different kinds of locusts has different curved line models which indicate differentia among species. There is no synchronological development between ovary and spermary. Under the comprehensive influence of ecological factors, the development of the genital organs of locusts which processes through the accurate regulation and control of the nerve and hormone finally readers the differentia of ovary and spermary in seasons and species. This differentia provides a kind of safeguard for genital isolation among species.3 By using measure and analysis in biological software, we observe the histological changes in ovarian development of ten kinds of locusts in Siping area. The results show that oogenesis basically accords with dividing criterion of three periods and eight stages according to the changes of the shape and amount of oocytes, nucleus, follicles and the synthesis and accumulation of alimentation and yolk protein and so on. In oogenesis, oocyte volume have an acute changes, especially in vitellogenesis, and the increasing of oocyte volume shows a growing model of a power series. The nuclear development of oocyte has great changes too. Follicles show significant changes in every stage which means they are controlled by oocytes accurately and periodically and provide accumulation of alimentation for the development of oocytes. In oogenesis, the species differentia exists in the changes of stages of the oocytes and the follicles. Vitellogenesis is a fateful physiological affair in oogenesis of insects and then it makes oocytes, nucleus and follicles change greatly in shape and function under the regulation of some hormone.4 In order to elucidate the role of c-kit in gametogenesis, we have examined immunohistochemically the expression of c-kit in the oogenesis and spermatogenesis of ten kinds of locusts in Siping area by measure and analysis through Motic Images Advanced3.2, a kind of image analysis system.There is c-kit positive special expression on each stage of spermatogenesis, but there are different positive expression levels. The results show that:(1)there is weak positive expression of c-kit in spermatogonia and positive granule is thinner;(2) there is a strong positive expression of c-kit in primary spermatocyte and positive granulebecomes biggest among all developmental periods; (3)c-kit positive expression becomes stronger in secondary spermatocyte while positive granule becomes thinner;(4)there is a strong positive expression of c-kit and thinner positive granule in mature sperm, which distributes on head and tail;(5)there is strong c-kit positive granule massing at the end of spermary;(6) there is c-kit positive granule in gland cell of spermathecae.In oogenesis, there is c-kit positive special expression with different expression level from the first stage to the sixth and there is no c-kit positive special expression from the seventh stage to the eighth. The results show that:(l)there is strong positive expression of c-kit in I stage and positive granule becomes biggest on this stage;(2) c-kit positive expression becomes weaker and thinner in â…¡ stage;(3)c-kit positive expression becomes stronger and bigger on â…¢-â…£stage;(4)c-kit positive expression has weaker and thinner tendency on â…¤-â…¥ stage;(5)c-kit positive expression disappears on â…¦-â…§ stage;(6)follicular cells have an ability to synthesize c-kit protein at the end of oogenesis and the c-kit positive granule are distributed to the egg shell;(7)there are c-kit positive granules in gland cell of oviduct.Furthermore, the intensity of c-kit positive expression of ten kinds of locusts in spermatogenesis and oogenesis is compared and analyzed. Results show that there are significant differences among different kinds of locusts. The phenomena might be the result of different kinds of locusts evolving with the ecological environment in behavior and physiology and even ensuring genital isolation.Above all, we can draw a conclusion that c-kit plays a crucial role in spermatogenesis and oogenesis and keeps the physiological action of sperm, egg, fertilization which recognizes each other between sperm and egg, and even is the important living factor for mature sperm and ovum.5 In the research of the dynamic change of c-kit positive expression in oogenesis and spermatogenesis of the dominant locusts of Siping area, we find that c-kit positive expression in oogenesis and spermatogenesis show a kind of a regular pattern of dynamic change. The peak of c-kit positive expression arrives at the beginning of locust development. With locust growth, various species show weaker tendency differently. This dynamic change of c-kit special expression shows that it becomes stronger in young periods than in old periods not only in spermatogenesis but also in oogenesis. And the dynamic change has significant difference in different kinds... |
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