Rodrigues-Oliveira Igor Henrique, Penteado Pierre Rafael, Pasa Rubens, Menegídio Fabiano Bezerra, Kavalco Karine Frehner
Universidade Federal de Viçosa, Laboratório de Genética Ecológica e Evolutiva, Rio Paranaíba, MG, Brazil.
Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Belo Horizonte, MG, Brazil.
Genet Mol Biol. 2023 Jul 10;46(3):e20230044. doi: 10.1590/1678-4685-GMB-2023-0044. eCollection 2023.
Deuterodon is a genus of the subfamily Stethaprioninae, a group of Neotropical fish known as tetras. Deuterodon hastatus represents a species complex, which is supported by cytogenetic and molecular data. In this study, we show the results of comparative evolutionary analyses of the ATP synthase subunit 6 gene in four Deuterodon species, in addition to ribosomal markers (18S rDNA and 5S rDNA), of a new population of the D. hastatus species complex from the Angra dos Reis/RJ region. The study population comprised a new cytotype, which we refer to as cytotype D, in D. hastatus, with 2n = 50 = 6M+8SM+8ST+28A. We obtained three different clades of D. hastatus in our phylogeny, one of them composed only by specimens of cytotype D. By using molecular clock dating, we observed that the radiation of Deuterodon from southeastern Brazil seemed to be associated with neotectonic events that occurred during the Miocene-Pliocene and Pliocene-Pleistocene transitions, marked by the capture of headwater streams and marine transgressions. The results obtained reinforce the idea that D. hastatus is a species complex, and at least three evolutionary significant units were identified in this group.
德氏脂鲤属是南美脂鲤亚科的一个属，是一群被称为灯鱼的新热带鱼类。哈氏德氏脂鲤代表一个物种复合体，这得到了细胞遗传学和分子数据的支持。在本研究中，我们展示了对四种德氏脂鲤的ATP合酶亚基6基因进行比较进化分析的结果，此外还分析了来自里约热内卢州安格拉杜斯雷斯地区的哈氏德氏脂鲤物种复合体一个新种群的核糖体标记（18S rDNA和5S rDNA）。研究种群包括哈氏德氏脂鲤中的一种新细胞型，我们将其称为细胞型D，其染色体数目为2n = 50 = 6M+8SM+8ST+28A。在我们的系统发育分析中，我们获得了哈氏德氏脂鲤的三个不同分支，其中一个仅由细胞型D的标本组成。通过使用分子钟定年法，我们观察到巴西东南部德氏脂鲤的辐射似乎与中新世 - 上新世和上新世 - 更新世过渡期间发生的新构造事件有关，这些事件的特征是源头溪流的捕获和海侵。所获得的结果强化了哈氏德氏脂鲤是一个物种复合体的观点，并且在这一组中至少鉴定出了三个具有进化意义的单元。
