Germ cell nests in adult ovaries and an unusually large ovarian reserve in the naked mole-rat.
Germ cell nests in adult ovaries and an unusually large ovarian reserve in the naked mole-rat.
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DOI：
10.1530/rep-20-0304
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发表时间：
2021-01
期刊：
影响因子：
--
通讯作者：
Holmes MM
中科院分区：
文献类型：
--
作者：
Place NJ;Prado AM;Faykoo-Martinez M;Brieño-Enriquez MA;Albertini DF;Holmes MM
裸色鼹鼠(核磁共振，无毛异头鼠)以其健康和超长的寿命(>；30岁)而闻名，相对于其较小的身体(35-40克)。核磁共振的一个现象受到的关注要少得多，那就是女性在活到第三个十年时，生育力或繁殖力没有下降。在许多哺乳动物物种中，生殖衰退的开始年龄与性成熟年龄保留的生殖细胞的数量密切相关。我们在NMRS中量化了最小年龄(6个月)的卵巢储备大小，当时从属雌性在脱离女王抑制后可以开始排卵。然后，我们将核磁共振卵巢储备大小与之前报道的其他19种哺乳动物的值进行了比较。6个月龄的核磁共振卵巢储备非常大，为108,588±69,890个原始卵泡，比同等大小的哺乳动物大10倍以上。我们还在6个月大的NMRS的卵巢中观察到生殖细胞巢，这是非常不寻常的，因为在其他哺乳动物中，生殖细胞巢的破裂和原始毛囊的形成通常在出生后早期完成。此外，我们在1.25岁至3.75岁的年轻成年NMR中发现了生殖细胞巢，在生殖激活和抑制的雌性中都有。异常大的核磁共振卵巢储备为解释该物种长期生育提供了一种机制。成年卵巢中的生殖细胞巢是否有助于核磁共振的长繁殖寿命仍有待确定。
The naked mole-rat (NMR, Heterocephalus glaber) is renowned for its eusociality and exceptionally long lifespan (> 30 y) relative to its small body size (35-40 g). A NMR phenomenon that has received far less attention is that females show no decline in fertility or fecundity into their third decade of life. The age of onset of reproductive decline in many mammalian species is closely associated with the number of germ cells remaining at the age of sexual maturity. We quantified ovarian reserve size in NMRs at the youngest age (6 months) when subordinate females can begin to ovulate after removal from the queen’s suppression. We then compared the NMR ovarian reserve size to values for 19 other mammalian species that were previously reported. The NMR ovarian reserve at 6 months of age is exceptionally large at 108,588 ± 69,890 primordial follicles, which is more than 10-fold larger than in mammals of a comparable size. We also observed germ cell nests in ovaries from 6-month-old NMRs, which is highly unusual since breakdown of germ cell nests and the formation of primordial follicles is generally complete by early postnatal life in other mammals. Additionally, we found germ cell nests in young adult NMRs between 1.25 and 3.75 years of age, in both reproductively activated and suppressed females. The unusually large NMR ovarian reserve provides one mechanism to account for this species’ protracted fertility. Whether germ cell nests in adult ovaries contribute to the NMR’s long reproductive lifespan remains to be determined.