Souza Lucas H B, Ferro Juan M, Milanez Helena M, Haddad Célio F B, Lourenço Luciana B
Laboratório de Estudos Cromossômicos (LabEsC), Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas, Campinas 13083-863, São Paulo, Brazil.
Laboratorio de Genética Evolutiva "Dr. Claudio J. Bidau", Instituto de Biología Subtropical (CONICET-UNaM), Facultad de Ciencias Exactas, Químicas y Naturales, Universidad Nacional de Misiones, Posadas 3300, Misiones, Argentina.
Biomolecules. 2025 Jun 16;15(6):876. doi: 10.3390/biom15060876.
Satellite DNAs (satDNAs) play a crucial role in understanding chromosomal evolution and the differentiation of sex chromosomes across diverse taxa, particularly when high karyotypic diversity occurs. The species complex comprises at least seven divergent lineages, each exhibiting specific karyotypic signatures. The group composed of , Lineage 1B of '' (L1B), and a lineage resulting from their secondary contact is especially intriguing due to varying degrees of sex chromosome heteromorphism. In this study, we characterized the satellitome of in order to identify novel satDNAs that may provide insights into chromosomal evolution, particularly concerning sex chromosomes. We identified 62 satDNAs in , collectively accounting for approximately 10% of the genome. Notably, nine satDNA families were shared with species from distantly related clades, raising questions about their potential roles in anurans genomes. Among the seven satDNAs mapped via fluorescent in situ hybridization, PepSat3 emerged as a strong candidate for the centromeric sequence in this group. Additionally, PepSat11 and PepSat24 provided evidence supporting a translocation involving both arms of the W chromosome in . Furthermore, a syntenic block composed of PepSat3, PcP190, and PepSat11 suggested an inversion event during the divergence of and L1B. The variation in signal patterns of satDNAs associated with nucleolar organizer regions (NORs) highlights the complexity of NOR evolution in this species complex, which exhibits substantial diversity in this genomic region. Additionally, our findings for PepSat30-350 emphasize the importance of validating the sex-biased abundance of satDNAs.
卫星DNA（satDNA）在理解不同分类群的染色体进化和性染色体分化方面起着至关重要的作用，特别是在出现高核型多样性的情况下。该物种复合体至少包括七个不同的谱系，每个谱系都表现出特定的核型特征。由[具体物种]、[物种名称]的1B谱系（L1B）以及它们二次接触产生的一个谱系组成的群体，由于不同程度的性染色体异形性，特别引人关注。在本研究中，我们对[具体物种]的卫星基因组进行了特征分析，以鉴定可能为染色体进化，特别是关于性染色体进化提供见解的新型satDNA。我们在[具体物种]中鉴定出62种satDNA，它们总共约占基因组的10%。值得注意的是，九个satDNA家族与远缘分支的物种共享，这引发了关于它们在无尾目动物基因组中潜在作用的疑问。在通过荧光原位杂交定位的七个satDNA中，PepSat3成为该群体着丝粒序列的有力候选者。此外，PepSat11和PepSat24提供了证据，支持[具体物种]中涉及W染色体双臂的易位。此外，由PepSat3、PcP190和PepSat11组成的一个同线区域表明，在[具体物种]和L1B分化过程中发生了一次倒位事件。与核仁组织区（NOR）相关的satDNA信号模式的变化突出了该物种复合体中NOR进化的复杂性，该复合体在这个基因组区域表现出大量的多样性。此外，我们对PepSat30 - 350的研究结果强调了验证satDNA性别偏向丰度的重要性。
