昆虫卵黄发生研究进展

昆虫卵黄发生研究进展李乾君，龚和，管致和（中国科学院动物研究所北京１０００８０）（北京农业大学植保系北京１０００９４）昆虫卵的成熟一般分为三个时期－－卵黄发生前期（Ｐｒｅｖｉｔｅｌｌｏｇｅｎｉｃｓｔａｇｅ）、卵黄发生期（ｖｉｔｅｌｌｏｇｅｎｉｃｓｔａ...

ADVANCES IN INSECT VITELLOGENESIS RESEARCH

in insect, vitellogenesis is a rather complicated process, which is aLfeeted by various external factors(eclosion, nutrition, mating, temperature etc.) andinternal factors(EDNH, JH, ecdysone, OOSH etc.). According to the mode of hormone regulation of Vg synthesis, insects can be divided into three groups.' In thefirst group, represented by Locusta migratorla, Rhodnius prolixal, Coccinclla septcmpunctata and cockroaches, JH is the only known hormone regulating Vg gene expression. In the second group, mainly Diptera (Added aegypti, Mecca domestica, andDrosophila mclanogastcr etc.), JH, ecdysone, EDNH and the midgut neurosecretorysystem are involved in the regulation of Vg synthesis. Ecdysone is the key hormonewhich regulates Vg synthesis in the fat body, and JH increases the competence ofthe fat body. In the third group, Lepidoptera, vitellogenesis is initiated either inpharate adults or in adults after eclosion, and both JH and ecdysone or either ofthe two hormones may be involved.Through the potency among the follicle epithelial cells, vitellogenin first getsto the surface of oocyte membrane, conjugates with the receptors in the membraneand then forms coated pits--coat vesicles-transitional yolk body, and finally yolkbody. In in bitro system, Vg uptake by oocyte is tissue-specific and saturable; it depends on the developing stage of oocyte, PH value, Vg concentration, Ca2+ and temperature. Oligosaccharides and positive charges bound to lysine residues in Vg areessentials for specific recognition by Vg receptors. Vg receptors were identified inLoci,sta migratoria, Aedes aegypti etc. JH increases Vg uptake in oocyte and Vgbinding to oocyte membrane. A possible route of hormonal regulation of vitellogenesis in housefly, Musca domestica, is proposed diagrammatically.