A common characteristic of sex chromosomes is the accumulation of repetitive DNA, which accounts for their diversification and degeneration. In grasshoppers, the X0 sex-determining system in males is considered ancestral. However, in some species, derived variants like neo-XY in males evolved several times independently by Robertsonian translocation. This is the case of Ronderosia bergii , in which further large pericentromeric inversion in the neo-Y also took place, making this species particularly interesting for investigating sex chromosome evolution. Here, we characterized the satellite DNAs (satDNAs) and transposable elements (TEs) of the species to investigate the quantitative differences in repeat composition between male and female genomes putatively associated with sex chromosomes. We found a total of 53 satDNA families and 56 families of TEs. The satDNAs were 13.5% more abundant in males than in females, while TEs were just 1.02% more abundant in females. These results imply differential amplification of satDNAs on neo-Y chromosome and a minor role of TEs in sex chromosome differentiation. We showed highly differentiated neo-XY sex chromosomes owing to major amplification of satDNAs in neo-Y. Furthermore, chromosomal mapping of satDNAs suggests high turnover of neo-sex chromosomes in R. bergii at the intrapopulation level, caused by multiple paracentric inversions, amplifications, and transpositions. Finally, the species is an example of the action of repetitive DNAs in the generation of variability for sex chromosomes after the suppression of recombination, and helps understand sex chromosome evolution at the intrapopulation level.

中文翻译：

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新性染色体的高活力：卫星 DNA 揭示了蚱蜢的复杂进化

性染色体的一个共同特征是重复 DNA 的积累，这是它们多样化和退化的原因。在蚱蜢中，雄性的 X0 性别决定系统被认为是祖先的。然而，在某些物种中，雄性中的新XY等衍生变体通过罗伯逊易位独立进化了几次。这就是 Ronderosia bergii 的情况，其中新 Y 也发生了进一步的大的着丝粒周围倒位，这使得该物种对于研究性染色体进化特别有趣。在这里，我们对该物种的卫星 DNA (satDNAs) 和转座因子 (TEs) 进行了表征，以研究假定与性染色体相关的男性和女性基因组之间重复组成的数量差异。我们共发现了 53 个 satDNA 家族和 56 个 TE 家族。男性的 satDNAs 比女性多 13.5%，而女性的 TEs 仅多 1.02%。这些结果意味着新 Y 染色体上 satDNA 的差异扩增和 TE 在性染色体分化中的次要作用。由于新Y中satDNA的主要扩增，我们显示出高度分化的新XY性染色体。此外，satDNAs 的染色体作图表明 R. bergii 中新性染色体在种群内水平上的高周转率是由多个中心倒位、扩增和转座引起的。最后，该物种是重复 DNA 在抑制重组后产生性染色体变异性的一个例子，