背景回顾：Sex chromosome evolution is thought to be tightly associated with the acquisition and maintenance of sexual dimorphisms. Plant sex chromosomes have evolved independently in many lineages and can provide a powerful comparative framework to study this. 

主要发现：We assembled and annotated genome sequences of three kiwifruit species (genus Actinidia) and uncovered recurrent sex chromosome turnovers in multiple lineages. 

结果1-性染色体演化：Specifically, we observed structural evolution of the neo-Y chromosomes, which was driven via rapid bursts of transposable element insertions. Surprisingly, sexual dimorphisms were conserved in the different species studied, despite the fact that the partially sex-linked genes differ between them. 

结果2-单基因控制：Using gene editing in kiwifruit, we demonstrated that one of the two Y-chromosome-encoded sex-determining genes, Shy Girl, shows pleiotropic effects that can explain the conserved sexual dimorphisms. 

结论：These plant sex chromosomes therefore maintain sexual dimorphisms through the conservation of a single gene, without a process involving interactions between separate sex-determining genes and genes for sexually dimorphic traits.

性染色体演化被认为与性别二态性的获取和维持息息相关。植物性染色体已经在许多谱系中独立演化，为针对这一问题的研究提供了理想材料。本文中，作者组装并注释了三个猕猴桃的基因组，发现了性染色体在多个谱系中反复翻转。其中，作者在新形成的Y染色体上观察到了结构演化，主要是由快速的转座元件插入的爆发所驱动。有趣的是，性别二态性在所研究的植物中是保守的，尽管他们之间性别连锁的基因部分不同。利用猕猴桃基因编辑技术，作者发现两个Y染色体上编码的性别决定基因其中之一，即Shy Girl表现出多效性功能，能够解释保守的性别二态性。因此，通过单个基因的保守性来维持这些植物的性染色体，而不涉及不同性别决定基因以及性别二态性状基因之间的相互作用。

** Takashi Akagi **