Early gonad development in zebrafish (Danio rerio)
Early gonad development in zebrafish (Danio rerio)
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DOI：
10.5897/ajb2014.13679
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发表时间：
2014-08
影响因子：
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通讯作者：
G. Okuthe;S. Hanrahan;B. Fabian
中科院分区：
文献类型：
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作者：
G. Okuthe;S. Hanrahan;B. Fabian
斑马鱼的性腺发生经历了最初的卵巢阶段，然后进入卵巢或睾丸阶段。生殖细胞如何选择进入卵子发生的命运并进入减数分裂，或者不进入减数分裂并进入精子发生的命运仍然是一个关键问题。本研究调查事件早期性腺发生在斑马鱼的目的是解开周围的有丝分裂/减数分裂转变在少年卵巢的事件。原始生殖细胞在受精后8天（dpf）鉴定。有丝分裂在15 dpf明显，减数分裂开始在一些性腺后22 dpf。40 dpf后，雌性性腺含有各种生殖细胞，包括卵原细胞，粗线期后和早期前卵黄发生的卵母细胞，而在一些性腺中，观察到退化的粗线期后的卵母细胞和增殖的生殖细胞。退化的卵母细胞以及在后性腺中相对较大比例的增殖的“性腺”生殖细胞的发生被认为是生精活动的第一个迹象，标志着次级（睾丸）性腺发生的开始。在此不能确定原始生殖细胞是否参与次级性腺发生。虽然这种现象在斑马鱼卵巢的机制没有得到很好的解决，在这里可以看到在凋亡调控的背景下。关键词：斑马鱼，性腺，有丝分裂/减数分裂转换，发育，性反转。
Gonadogenesis in zebrafish goes through an initial ovarian phase then subsequently into either ovarian or testicular phases. How germ cells choose to commit to an oogenic fate and enter meiosis or alternatively not enter meiosis and commit to a spermatogenetic fate remains a key question. This study investigated events of early gonadogenesis in zebrafish with the aim of unraveling the events surrounding the mitotic/meiotic transition in juvenile ovaries. Primordial germ cells were identified at eight days post fertilization (dpf). Mitotic divisions were apparent at 15 dpf, and meiosis initiated in some gonads after 22 dpf. After 40 dpf, female gonads contained various germ cells including oogonia, post-pachytene and early pre-vitellogenic oocytes, whereas in some gonads, degenerative post-pachytene oocytes and proliferating germ were observed. The occurrence degenerating oocytes as well as a relatively larger proportion of proliferating "gonial" germ cells in the latter gonads was considered the first indication of spermatogenic activity, marking the onset of secondary (testicular) gonadogenesis. It could not be determined here whether primordial germ cells were involved in secondary gonadogenesis. While the mechanisms of this phenomenon in zebrafish ovaries are not well addressed, here it can be seen in the context of an apoptotic regulation. Key words: Danio rerio, gonad, mitotic/meiotic transition, development, sex inversion.