Geysen Johan, Cardoen Johan, Van Eynde Sigrid, Geens Carine, De Loof Arnold
Zoological Institute, University of Leuven, Naamsestraat 59, B-3000, Leuven, Belgium.
Rouxs Arch Dev Biol. 1988 Mar;197(2):101-109. doi: 10.1007/BF00375932.
Polar organisation in the follicles of adult Sarcophaga bullata is reflected in the nurse cell-oocyte axis and in the orientation of the two polar cell pairs in the follicular epithelium. The internal organisation of the nurse cell chamber contributes to polarity but not to dorsoventral asymmetry. Dorsoventral asymmetry is correlated with the eccentric position of the germinal vesicle and the orientation of the polar cell pairs; no other follicle cell specialisations are seen. In an ovary, follicles are preferentially orientated with the dorsal side to the centre of the ovary. Cytoskeletal and some haemolymph proteins are molecular markers of polarity. Thus, in pre-vitellogenic stages, tubulin immunoreactivity is higher in the oocyte than in the nurse cells, actin immunoreactivity is the same over the cystocytes and larval serum proteins are restricted to the poles. During vitellogenesis, both actin and tubulin become more concentrated in the nurse cells and larval serum protein 1 accumulated in the polar cells during border cell migration when yolk polypeptides also accumulate in the oocyte. At the end of vitellogenesis a lipophorin is taken up by the oocyte. No molecular marker of dorsoventral asymmetry was identified.
成年肉蝇卵泡中的极性组织反映在滋养细胞-卵母细胞轴以及卵泡上皮中两个极性细胞对的方向上。滋养细胞腔的内部组织有助于极性形成，但与背腹不对称无关。背腹不对称与生发泡的偏心位置和极性细胞对的方向相关；未观察到其他卵泡细胞特化现象。在卵巢中，卵泡优先以背侧朝向卵巢中心排列。细胞骨架蛋白和一些血淋巴蛋白是极性的分子标记。因此，在卵黄发生前期，卵母细胞中的微管蛋白免疫反应性高于滋养细胞，肌动蛋白免疫反应性在囊细胞中相同，而幼虫血清蛋白局限于两极。在卵黄发生期间，肌动蛋白和微管蛋白在滋养细胞中都变得更加集中，并且在边界细胞迁移期间，当卵黄多肽也在卵母细胞中积累时，幼虫血清蛋白1在极性细胞中积累。在卵黄发生末期，卵母细胞摄取了一种脂蛋白。未鉴定出背腹不对称的分子标记。
