Differentiation Of Gonad And Immunolocalization Of Vitellogenesis In Neocaridina Denticulata Sinensis

Neocaridina denticulata sinensis belongs to Crustacea, Decapoda, Atyidae, Neocaridina. N. denticulata sinensis has many characters such as strong adaptability and quick propagation, so it is a good material in ecological, physiological and toxicological experiments.The process of gonadal development and differentiation were observed by optical microscope and transmission electron microscope (TEM). The occurrence and accumulation characters of Vitellin (Vn) during gonadal development were researched by immunohistochemical technique. On the one hand, it provided the basic information for reproductive biology and environmental biology; on the other hand, it would be theoretical and practical significance for reproductive and developmental regulation and genetic breeding of crustaceans.N. denticulata sinensis gonadal occurrence and development:On 3 to 6 days post hatching is the period of PGCs migration and gonadal primordia formation. First, PGCs migrated from the cradle along the back arteries and the digestive tract. Then, PGCs and several PMC (primary mesenchme cells) gathered at the both sides of dorsal artery near the top of the mid-gut, constituted the undifferentiated genital ridge. Then PGCs reproduced continuously, the size of PGCs markedly increased, gonadal primordium had two symmetrical regions near the top of the mid-gut, and the capsule surrounded the gonadal primordium, the capsule marked that the gonadal primordium had been formed. From the PGCs migration to the gonadal primordium formation, according to the cell morphology, PGCs would be divided into three periods: Phaseâ… PGCs, Phaseâ…¡PGCs and Phaseâ…¢PGCs.N. denticulata sinensis ovary differentiation and development:On 10 days post hatching, ovarian cavity formed, there were four types of cell in the ovarian cavity: phaseâ…¢PGCs, transitional cells, the early oogonia and some PMC distributed around the oogonia.On 13 days post hatching, PGCs disappeared and the oogonia volume increased significantly, the nucleoli was prominent. The number of organelles in the cytoplasm was increased, there were many mitochondria, lysosome, ribosome and Golgi.N. denticulata sinensis testis differentiation and development:On 23 days post hatching, testis began the differentiation, mesenchymal cells arranged around and formed the early testis, the testes of this period still had incomplete capsula, there were two periods of cells: one was phaseâ…¢PGCs, the other one was the transitional cells.On 35 days post hatching, the PGCs in testes disappeared at this time, and the number of androgone became increased, androgone surrounded by supporting cells.The results of immunohistochemistry research showed that the ovaries appeared early vitellogenesis oocyte (OC2) on 70 days post hatching, there were Vn granules in the cytoplasm, Vn granules evenly distributed in the cytoplasm. On 82 days post hatching, mid-vitellogenesis oocyte (OC3) appeared in the ovary, the cell volume increased significantly at this time, massive spherical Vn appeared at the edge of cytoplasm, it indicated that a large number of Vn was synthesizing in this period.