日本大阪大学Makoto Tachibana研究小组在研究中取得进展。他们发现小鼠Sry基因座带有一个隐性外显子，这对于雄性性别决定至关重要。相关论文发表在2020年10月2日出版的《科学》杂志上。

他们鉴定了小鼠Sry的一个隐秘第二外显子和一个对应的双外显子类型的Sry（Sry-T）转录本。 缺少Sry-T的XY小鼠发生性别逆转，Sy-T在XX小鼠中异位表达诱导雄性发育。Sry-T信使RNA的表达与标准单外显子型Sry（Sry-S）相似，但SRY-T蛋白显著表达是因为在SRY-S的C末端不存在degron。

通过获得反转录转座子来源的编码序列来取代degron，Sry 外显子2最近报道也出现在小鼠中。他们的发现表明，在自然界中，SRY-T（而非SRY-S）是真正的睾丸决定因素。

据了解，哺乳动物的性别决定基因Sry诱导雄性发育。自30年前发现以来，Sry被认为是单外显子基因。

附：英文原文

Title: The mouse Sry locus harbors a cryptic exon that is essential for male sex determination

Author: Shingo Miyawaki, Shunsuke Kuroki, Ryo Maeda, Naoki Okashita, Peter Koopman, Makoto Tachibana

Issue&Volume: 2020/10/02

Abstract: The mammalian sex-determining gene Sry induces male development. Since its discovery 30 years ago, Sry has been believed to be a single-exon gene. Here, we identified a cryptic second exon of mouse Sry and a corresponding two-exon type Sry (Sry-T) transcript. XY mice lacking Sry-T were sex-reversed, and ectopic expression of Sry-T in XX mice induced male development. Sry-T messenger RNA is expressed similarly to that of canonical single-exon type Sry (Sry-S), but SRY-T protein is expressed predominantly because of the absence of a degron in the C terminus of SRY-S. Sry exon2 appears to have evolved recently in mice through acquisition of a retrotransposon-derived coding sequence to replace the degron. Our findings suggest that in nature, SRY-T, not SRY-S, is the bona fide testis-determining factor.

DOI: 10.1126/science.abb6430

Source: https://science.sciencemag.org/content/370/6512/121