A Structurally and Functionally Common Unit in Testes and Ovaries of Medaka (Oryzias latipes), a Teleost Fish
A Structurally and Functionally Common Unit in Testes and Ovaries of Medaka (Oryzias latipes), a Teleost Fish
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DOI：
10.1159/000447313
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发表时间：
2016-07
影响因子：
2.3
通讯作者：
T. Nishimura;Shuhei Nakamura;Minoru Tanaka
中科院分区：
文献类型：
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作者：
T. Nishimura;Shuhei Nakamura;Minoru Tanaka
睾丸和卵巢是结构和功能不同的器官，但它们起源于同一性腺原基。在这里，我们提出了一个由生殖细胞和sox9b表达细胞组成的组织如何由基底膜形成一个功能共同的单位，在成年青鳉的卵巢和睾丸中保留性无关或不固定的生殖系干细胞。在睾丸发育过程中，该单位扩大并产生小叶，其中生殖干细胞不断产生大量精子，而女性中的单位成为生殖摇篮，代表新卵子发生的生态位区域。最近在雌性foxl3突变体中的发现表明，该单位也可以作为生殖干细胞在卵巢中持续产生精子的小生境。我们推测，这一单位在青鳉可能对应于髓质索的性腺原基在卵巢发育过程中的髓质索的碎片可能与生殖系干细胞的情况下。
Testes and ovaries are structurally and functionally different organs, but they originate from the same gonadal primordium. Here, we propose how a tissue composed of germ cells and sox9b-expressing cells underlain by a basement membrane develops a functionally common unit that reserves sexually indifferent or unfixed germline stem cells in both the ovaries and testes of adult medaka. During testicular development, the unit expands and gives rise to lobules where germline stem cells continuously produce a tremendous amount of sperm, while the unit in the female becomes germinal cradles that represent niche areas for neo-oogenesis. A recent finding in female foxl3 mutants demonstrates that the unit can also serve as the niche for germline stem cells continuously producing sperm in the ovary. We hypothesize that this unit in medaka might correspond to the medullary cords of the gonadal primordium in amniotes and that fragmentation of the medullary cords during ovarian development may be related to the absence of germline stem cells.