She Hongbing, Xu Zhaosheng, Zhang Helong, Wu Jian, Wang Xiaowu, Liu Zhiyuan, Qian Wei
Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Biology (Basel). 2022 Jul 29;11(8):1138. doi: 10.3390/biology11081138.
The sex-linked region (SLR) plays an important role in determining the sex of a plant. The SLR of the Y chromosome, composed of a 14.1-Mb inversion and a 10-Mb Y-duplication region (YDR), was deciphered in previously. However, our understanding of the SLR in its wild relatives, and , remains limited. In this study, we used 63 resequencing data from the three species to infer the evolution of the SLR among the species. In the SLR, all the cultivated spinach and accessions were clustered into two distinct categories with both sexes, while the accessions of both sexes were grouped. This suggests that shared a similar SLR with , but not with , which was further confirmed based on the population structure and principal component analysis. Furthermore, we identified 3910 fully sex-linked SNPs in and 92.82% of them were available in , while none of the SNPs were adopted in . Genome coverage in males and females supported the hypothesis that the YDR increasingly expanded during its evolution. Otherwise, we identified 13 sex-linked transposable element insertion polymorphisms within the inversion in both and , demonstrating that the transposable element insertions might have occurred before the recombination suppression event of the inversion. The SLR was conserved compared with the pseudoautosomal region given that the genetic hitchhiking process occurred in the SLR during its evolution. Our findings will significantly advance our understanding of the characteristics and evolution of the SLR in species.
性连锁区域（SLR）在决定植物性别方面起着重要作用。Y染色体的SLR由一个14.1兆碱基的倒位和一个10兆碱基的Y重复区域（YDR）组成，此前已被破译。然而，我们对其野生近缘种和中的SLR的了解仍然有限。在本研究中，我们使用了来自三个物种的63个重测序数据来推断物种间SLR的进化。在SLR中，所有栽培菠菜和的种质都被聚类为两个不同的两性类别，而两性的种质则被归为一组。这表明与共享相似的SLR，但与不共享，基于群体结构和主成分分析进一步证实了这一点。此外，我们在中鉴定出3910个完全性连锁的单核苷酸多态性（SNP），其中92.82%在中可用，而在中没有采用任何SNP。雄性和雌性的基因组覆盖支持了YDR在其进化过程中逐渐扩大的假设。否则，我们在和的倒位中鉴定出13个性连锁转座元件插入多态性，表明转座元件插入可能发生在倒位的重组抑制事件之前。与假常染色体区域相比，SLR是保守的，因为在其进化过程中，遗传搭便车过程发生在SLR中。我们的发现将显著推进我们对物种中SLR的特征和进化的理解。
