Satellites are an abundant source of repetitive DNAs that play an essential role in the chromosomal organization and are tightly linked with the evolution of sex chromosomes. Among fishes, Triportheidae stands out as the only family where almost all species have a homeologous ZZ/ZW sex chromosomes system. While the Z chromosome is typically conserved, the W is always smaller, with variations in size and morphology between species. Here, we report an analysis of the satellitome of Triportheus auritus (TauSat) by integrating genomic and chromosomal data, with a special focus on the highly abundant and female-biased satDNAs. In addition, we investigated the evolutionary trajectories of the ZW sex chromosomes in the Triportheidae family by mapping satDNAs in selected representative species of this family. The satellitome of T. auritus comprised 53 satDNA families of which 24 were also hybridized by FISH. Most satDNAs differed significantly between sexes, with 19 out of 24 being enriched on the W chromosome of T. auritus. The number of satDNAs hybridized into the W chromosomes of T. signatus and T. albus decreased to six and four, respectively, in accordance with the size of their W chromosomes. No TauSat probes produced FISH signals on the chromosomes of Agoniates halecinus. Despite its apparent conservation, our results indicate that each species differs in the satDNA accumulation on the Z chromosome. Minimum spanning trees (MSTs), generated for three satDNA families with different patterns of FISH mapping data, revealed different homogenization rates between the Z and W chromosomes. These results were linked to different levels of recombination between them. The most abundant satDNA family (TauSat01) was exclusively hybridized in the centromeres of all 52 chromosomes of T. auritus, and its putative role in the centromere evolution was also highlighted. Our results identified a high differentiation of both ZW chromosomes regarding satellites composition, highlighting their dynamic role in the sex chromosomes evolution.

卫星是重复 DNA 的丰富来源，在染色体组织中起着重要作用，并与性染色体的进化密切相关。在鱼类中，Triportheidae 是唯一一个几乎所有物种都具有同源 ZZ/ZW 性染色体系统的科。虽然 Z 染色体通常是保守的，但 W 总是较小，物种之间的大小和形态各不相同。在这里，我们报告了对Triportheus auritus卫星的分析(TauSat) 通过整合基因组和染色体数据，特别关注高度丰富和偏向女性的 satDNA。此外，我们通过在该科的选定代表性物种中绘制 satDNA，研究了 Triportheidae 科 ZW 性染色体的进化轨迹。T. auritus的卫星组包含 53 个 satDNA 家族，其中 24 个也通过 FISH 杂交。大多数 satDNA 在性别之间存在显着差异，24 个中有 19 个富集在T. auritus的 W 染色体上。与T. signatus和T. albus的 W 染色体杂交的 satDNA 数量根据其 W 染色体的大小，分别减少到六个和四个。没有 TauSat 探针在 Agoniates halecinus 的染色体上产生 FISH 信号。尽管它具有明显的保守性，但我们的结果表明每个物种在 Z 染色体上的 satDNA 积累都不同。为具有不同 FISH 映射数据模式的三个 satDNA 家族生成的最小生成树 (MST) 揭示了 Z 和 W 染色体之间不同的同质化率。这些结果与它们之间不同程度的重组有关。最丰富的 satDNA 家族 (TauSat01) 完全杂交于T. auritus所有 52 条染色体的着丝粒, 并且还强调了它在着丝粒进化中的推定作用。我们的结果确定了两个 ZW 染色体在卫星组成方面的高度分化，突出了它们在性染色体进化中的动态作用。