The dorsoventral polarity of Drosophila egg is established by means of signaling between the germ line-derived oocyte and the surrounding somatic follicle cells.

果胚胎的发育是由四种系统，别控制头尾、前、后以及腹的形成。

In the posterior segment, its dorsoventral axis was the longest, and could be divided into two parts: the dorsal and the ventral parts.

后段的腹径最长，可侧和腹侧，两的细胞界清晰。