Frankenberg S, Selwood L
Department of Zoology, La Trobe University, Bundoora, Victoria, Australia.
Mol Reprod Dev. 2001 Mar;58(3):297-306. doi: 10.1002/1098-2795(200103)58:3<297::AID-MRD8>3.0.CO;2-C.
Marsupial ova are slightly larger on average than those of eutherians. They have often been described as "yolky", although the nature and roles of their contents in later development are poorly understood. In the ova of all marsupial species studied, large quantities of electron-lucent vesicles are present. This study describes the ultrastructure of oogenesis in the brushtail possum, Trichosurus vulpecula. Oocytes of primordial follicles contain a variety of organelles of unknown function, some of which have been described previously in bandicoots. Large electron-lucent vesicles begin to accumulate after the transition from primordial follicle to primary follicle and are derived at least partly from the Golgi and endoplasmic reticulum. Other inclusions that are absent in some other marsupial species are present in growing possum oocytes in smaller quantities, including yolklike lipid bodies and electron-dense granular bodies.
有袋类动物的卵子平均而言比有胎盘类动物的卵子略大。它们常被描述为“富含卵黄的”，尽管人们对其内容物在后期发育中的性质和作用了解甚少。在所有已研究的有袋类物种的卵子中，都存在大量电子透明小泡。本研究描述了帚尾袋貂（Trichosurus vulpecula）卵子发生的超微结构。原始卵泡的卵母细胞含有多种功能未知的细胞器，其中一些先前已在袋狸中被描述过。从原始卵泡向初级卵泡转变后，大型电子透明小泡开始积累，并且至少部分源自高尔基体和内质网。其他一些有袋类物种中不存在的内含物，在生长中的袋貂卵母细胞中数量较少，包括卵黄样脂质体和电子致密颗粒体。
