Mouse TEX14 Is Required for Embryonic Germ Cell Intercellular Bridges but Not Female Fertility
Mouse TEX14 Is Required for Embryonic Germ Cell Intercellular Bridges but Not Female Fertility
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DOI：
10.1095/biolreprod.108.070649
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发表时间：
2009-03-01
影响因子：
3.6
通讯作者：
Matzuk, Martin M.
中科院分区：
文献类型：
--
作者：
Greenbaum, Michael P.;Iwamori, Naoki;Matzuk, Martin M.
生殖细胞胞质分裂的一个保守特征是在子细胞之间形成稳定的细胞间桥。这些细胞间桥在从黑腹果蝇到智人的不同物种中可见，并已被证明在大量生殖细胞的通信中发挥作用。在睾丸表达基因14（Tex 14）敲除小鼠中，精子发生过程中细胞间桥不形成，雄性小鼠不育，表明细胞间桥在哺乳动物出生后精子发生中起重要作用。在雄性和雌性胚胎中，分裂的生殖细胞之间也形成细胞间桥。然而，对哺乳动物胚胎细胞间桥的形成或作用知之甚少。在女性中，胚胎细胞间桥被认为在推定卵母细胞的发育中起作用。在这里，我们表明，TEX 14是男性和女性胚胎细胞间桥的重要组成部分。此外，我们证明，有丝分裂驱动蛋白样蛋白1（MKLP 1，官方符号KIF 23），我们已经发现，这是一个组成部分的细胞间桥在精子发生过程中，也是一个组成部分的男性和女性胚胎细胞间桥。生殖细胞细胞间的桥梁很容易确定的KIF 23免疫荧光之间的生殖母细胞和卵原细胞的对照小鼠，但不存在之间的生殖细胞的Tex 14-null小鼠。此外，通过电子显微镜观察，细胞间桥存在于所有对照新生儿卵巢中，但在Tex 14敲除卵巢中不存在。尽管没有胚胎细胞间桥的Tex 14-null小鼠，雄性小鼠启动精子发生，和雌性小鼠是可育的。尽管Tex 14缺失的新生儿卵巢中卵母细胞较少，但1岁时卵泡生成仍然活跃。因此，虽然TEX 14和细胞间桥在出生后精子发生中具有重要作用，但它们在胚胎中并不需要。
A conserved feature of germ cell cytokinesis is the formation of stable intercellular bridges between daughter cells. These intercellular bridges are seen in diverse species from Drosophila melanogaster to Homo sapiens and have been shown to have roles in communication of large numbers of germ cells. In testis expressed gene 14 (Tex14) knockout mice, intercellular bridges do not form during spermatogenesis, and male mice are sterile, demonstrating an essential role for intercellular bridges in postnatal spermatogenesis in mammals. Intercellular bridges also form between dividing germ cells in both male and female embryos. However, little is known about the formation or role of the embryonic intercellular bridges in mammals. In females, embryonic intercellular bridges have been proposed to have a role in development of the presumptive oocyte. Herein, we show that TEX14 is an essential component of male and female embryonic intercellular bridges. In addition, we demonstrate that mitotic kinesin-like protein 1 (MKLP1, official symbol KIF23), which we have discovered is a component of intercellular bridges during spermatogenesis, is also a component of male and female embryonic intercellular bridges. Germ cell intercellular bridges are readily identified by KIF23 immunofluorescence between the gonocytes and oogonia of control mice but are absent between germ cells of Tex14-null mice. Furthermore, by electron microscopy, intercellular bridges are present in all control newborn ovaries but are absent in the Tex14 knockout ovaries. Despite the absence of embryonic intercellular bridges in the Tex14-null mice, male mice initiate spermatogenesis, and female mice are fertile. Although fewer oocytes were present in Tex14-null neonatal ovaries, folliculogenesis was still active at 1 yr of age. Thus, while TEX14 and intercellular bridges have an essential role in postnatal spermatogenesis, they are not required in the embryo.