Miyado Mami, Yoshida Kaoru, Miyado Kenji, Katsumi Momori, Saito Kazuki, Nakamura Shigeru, Ogata Tsutomu, Fukami Maki
Department of Molecular Endocrinology, National Research Institute for Child Health and Development, Tokyo 157-8535, Japan.
Faculty of Biomedical Engineering, Toin University of Yokohama, Yokohama 225-8502, Japan.
Int J Mol Sci. 2017 Jun 19;18(6):1300. doi: 10.3390/ijms18061300.
MAMLD1 has been implicated in testicular function in both human and mouse fetuses. Although three patients with mutations were reported to have hypergonadotropic hypogonadism in their teens, the functional significance of MAMLD1 in the postnatal testis remains unclear. Here, we analyzed the phenotype of knockout (KO) male mice at reproductive ages. The reproductive organs of KO male mice were morphologically unremarkable, except for relatively small testes. Seminiferous tubule size and number of proliferating spermatogonia/spermatocytes were reduced in the KO testis. Daily sperm production of KO mice was mildly attenuated, whereas total sperm counts in epididymal semen remained normal. Sperm motility and morphology, as well as androgen levels in serum and testicular tissues and the number of pups born from cross-mated wildtype (WT) female mice, were comparable between WT and KO male mice. These results indicate that MAMLD1 contributes to the maintenance of postnatal testicular growth and daily sperm production but is dispensable for androgen biosynthesis and fertility. MAMLD1 likely plays supporting roles in multiple and continuous steps of male reproduction.
MAMLD1已被证明与人类和小鼠胎儿的睾丸功能有关。尽管有报道称三名携带突变的患者在青少年时期患有高促性腺激素性性腺功能减退，但MAMLD1在出生后睾丸中的功能意义仍不清楚。在这里，我们分析了生殖年龄的基因敲除（KO）雄性小鼠的表型。除了睾丸相对较小外，KO雄性小鼠的生殖器官在形态上没有明显异常。KO睾丸中的生精小管大小和增殖精原细胞/精母细胞数量减少。KO小鼠的每日精子产量略有下降，而附睾精液中的总精子数保持正常。野生型（WT）和KO雄性小鼠之间的精子活力和形态，以及血清和睾丸组织中的雄激素水平，以及与杂交的WT雌性小鼠所生幼崽的数量相当。这些结果表明，MAMLD1有助于维持出生后睾丸的生长和每日精子产量，但对于雄激素生物合成和生育能力是可有可无的。MAMLD1可能在雄性生殖的多个连续步骤中发挥支持作用。
