浙江大学周琦小组在研究中取得进展。他们探明了由转座因子介导的基因传递形成了古代蜥蜴性染色体的动态进化。相关论文于2025年8月18日发表于国际顶尖学术期刊《遗传学报》杂志上。

研究小组之前在蜥蜴Varanthem acanthurthem （Vac）中通过细胞遗传学定位发现其整个chrW（而非chrZ）与chr2部分同源，表明其复杂的性染色体进化历史尚待阐明。为了解决这个问题，课题组研究人员组装了一个染色体水平的基因组，并提供了证据，证明Vac性染色体对经历了至少两次重组丢失，产生了类似于鸟类和哺乳动物的进化阶层模式。与其他蜥蜴基因组的比较表明，在chrW和chr2上的重复基因对附近富集的特定反转录转座子亚家族逐步传播到变异性祖先。这些反转录转座子可能介导了chrW上常染色体基因的募集和扩增，包括犁鼻化学感觉受体基因家族V2R的成员。他们的研究结果表明，W或Y染色体作为重复元素的避难所，可能在其长期退化过程中反复招募负责两性二态性的短命功能基因。

研究人员表示，与鸟类和哺乳动物相比，蜥蜴通常表现出频繁的转换和更大的性别决定机制多样性，而起源于1.15亿年前的鳗形蜥蜴的保守性染色体ZW似乎是个例外。

附：英文原文

Title: Gene traffic mediated by transposable elements shaped the dynamic evolution of ancient sex chromosomes of varanid lizard

Author: Qi Zhou d a e f

Issue&Volume: 2025/08/18

Abstract: Lizards usually exhibit frequent turnovers and a much greater diversity of sex determination mechanisms compared to birds and mammals, with the conserved ZW sex chromosomes of anguimorph lizards originating over 115 million years ago a seeming exception. We previously discovered in an anguimorph lizard Varanus acanthurus (Vac) whose entire chrW, but not chrZ is homologous to part of the chr2 by cytogenetic mapping, suggesting its complex history of sex chromosome evolution yet to be elucidated. To address this, we assemble a chromosome-level genome, and provide evidence that the Vac sex chromosome pair has undergone at least two times of recombination loss, producing a pattern of evolutionary strata like that of birds and mammals. Comparison to other lizard genomes date the stepwise propagation of specific retrotransposon subfamilies enriched near the duplicated gene pairs on the chrW and chr2 to the varanid ancestor. These retrotransposons probably have mediated the recruitment and amplification of autosomal genes on the chrW, including members of a large vomeronasal chemosensory receptor gene family V2R. Our results suggest that the W or Y chromosome as a refugium of repetitive elements, may recurrently recruit short-lived functional genes responsible for sexual dimorphisms during its long-term course of degeneration.

DOI: 10.1016/j.jgg.2025.08.002

Source: https://www.sciencedirect.com/science/article/abs/pii/S1673852725002243