In mammals, more than 2,000 genes are specifically or abundantly expressed in testis, but gene knockout studies revealed several are not individually essential for male fertility. Tesmin (Metallothionein-like 5; Mtl5) was originally reported as a testis-specific transcript that encodes a member of the CXC motif containing metallothionein family. Later studies showed that Tesmin has two splicing variants and both are specifically expressed in male and female germ cells. Herein, we clarified that the long (Tesmin-L) and short (Tesmin-S) transcript forms start expressing from spermatogonia and the spermatocyte stage, respectively, in testis. Further, while Tesmin deficient female mice are fertile, male mice are infertile due to arrested spermatogenesis at the pachytene stage. We were able to rescue the infertility with a Tesmin-L transgene, where we concluded that TESMIN-L is critical for meiotic completion in spermatogenesis and indispensable for male fertility.

中文翻译：

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TESMIN，金属硫蛋白样 5，是小鼠精子发生所必需的†。

在哺乳动物中，超过 2,000 种基因在睾丸中特异性或大量表达，但基因敲除研究表明，其中一些基因对男性生育能力而言并不是必不可少的。Tesmin（Metallothionein-like 5；Mtl5）最初被报道为睾丸特异性转录物，其编码包含金属硫蛋白家族的 CXC 基序的成员。后来的研究表明，Tesmin 有两种剪接变体，并且都在雄性和雌性生殖细胞中特异性表达。在此，我们阐明了长 (Tesmin-L) 和短 (Tesmin-S) 转录形式分别从睾丸中的精原细胞和精母细胞阶段开始表达。此外，虽然 Tesmin 缺陷的雌性小鼠可以生育，但雄性小鼠由于在粗线期阶段精子发生停滞而不能生育。我们能够用 Tesmin-L 转基因挽救不孕症，