甜菜夜蛾胚胎发育的研究(Ⅰ)——卵裂、胚盘、胚带的形成及胚层分化

STUDIES ON THE EMBRYONIC DEVELOPMENT OF SPODOPTERA EXIGUA (HüBNER) (Ⅰ)──Cleavage,formation of blastederm and germ band, and differentiation of germinal layers

本文详细研究了甜菜夜蛾spodopteraexigua(H櫣ｂｎｅｒ)胚胎发育的卵裂、胚盘、胚带的形成和胚层分化。甜菜夜蛾卵的周质分两层 ;卵裂时子核以“彗星”状活质体向卵表面迁移 ,形成胚盘 ;卵黄逐渐形成卵黄球 ,内有 1～ 2个消黄细胞 ;卵腹面的胚盘细胞逐渐增厚为胚带 ,其他胚盘细胞发育成浆膜 ,浆膜刚一形成 ,羊膜即开始发生 ;随着原肠沟的出现 ,胚带分化为里、外两层 ,外层将来形成外胚层 ,里层形成中胚层和内胚层。

This paper studies the embryonic development of Spodoptera exigua(Hübner) including the cleavage, the formation of blastoderm and germ band, and the differentiation of germinal layers. The periplasm of eggs included two layers. Daughter nuclei moved towards the egg surface in the form of cometic energids to form blastoderm during the cleavage. The yolk gradually became yolk spheres which contained one or two vitellophages.The blastoderm cells on the egg venter developed into germ band, the other cells into serosa. The amnion began to grow shortly after the formation of serosa. The germ band was delaminated into two layers with the appearance of gastral groove. The outer layer would become the ectoderm and the inner would form the mesoderm and endoderm in the future.