Abstract: In the Japanese oak silkworm, Antheraea yamamai, the titre's dynamics of vitellogenin(Vg) or vitellin(Vt) and total soluble proteins in the fat body, haemolymph and ovary from larval cocooning to moth emerging were assayed. Vg was synthesized in the fat body, and its synthesis started on the 4th day after cocooning. The Vg titer both in the fat body and haemolymph began to increase on the 4th day after cocooning, reached the highest level on the 6th or 8th day after pupation, and markedly decreased on the 1st day after emergence. Vg initated to be uptaken by the ovary on the 1st day after pupation, and then the titer of yolk protein in the ovary gradually increased with the increase of pupal dayage and finally reached a plateau level. In the same ovariole, Vt content in an eggchamber gradually grew with the increase of egg-chamber volume from the apex to terminal egg-chamber (closest to the oviduct). In contrast to Vt titer in the eggchamber of the ovariole in the pupa with older day-age, it was markedly lower in the corresponding eggchamber of the ovariole in the pupa with younger dayage. There was a positive linear relationship between Vt content and eggchamber volume. The results acquired by electron microscopy indicated that Vg uptaken by oocyte was stored as yolk body. The size of yolk body in an oocyte changed with ovary development. At earlier stage of ovary development, its size was relatively smaller. In the same ovariole, yolk body's size showed smaller in the apex oocyte, and showed larger with a net shape in the terminal oocyte (closest to the oviduct).

Key words: Antheraea yamamai, vitellogenin, vitellin, yolk body