Department of Biology, University of Maryland, College Park, MD 20742, USA.
Institute of Biology, University of Graz, 8010 Graz, Austria.
Genome Biol Evol. 2024 Jul 3;16(7). doi: 10.1093/gbe/evae152.
African cichlid fishes are known for their high rates of phenotypic evolution. A rapid rate of diversification is apparent also in the diversity of their sex chromosomes. To date, sex determiners have been identified on 18 of 22 chromosomes in the standard karyotype. Here, we use whole-genome sequencing to characterize the sex chromosomes of seven populations of basal haplochromines, focusing on the genus Pseudocrenilabrus. We identify six new sex chromosome systems, including the first report of a cichlid sex-determining system on linkage group 12. We then quantify the rates and patterns of sex chromosome turnover in this clade. Finally, we test whether some autosomes become sex chromosomes in East African cichlids more often than expected by chance.
非洲丽鱼科鱼类以其高表型进化率而闻名。它们的性染色体多样性也表现出快速的多样化速度。迄今为止，在标准核型的 22 条染色体中，已经确定了 18 条性决定基因座。在这里，我们使用全基因组测序来描述 7 个基底丽鱼科种群的性染色体，重点是拟腹吸鳅属。我们确定了 6 种新的性染色体系统，包括首次在丽鱼科中报告的连锁群 12 上的性决定系统。然后，我们量化了这个分支中性染色体转换的速度和模式。最后，我们测试了东非丽鱼中一些常染色体成为性染色体的频率是否超过了随机预期。
