Soares R X, Bertollo L A C, Cioffi M B, Costa G W W F, F Molina W
Departamento de Biologia Celular e Genética, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, RN, Brasil.
Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, SP, Brasil.
Genet Mol Res. 2014 Apr 3;13(2):2470-9. doi: 10.4238/2014.April.3.19.
Dolphinfishes (Coryphaenidae) are pelagic predators distributed throughout all tropical and subtropical oceans and are very important for commercial, traditional, and sport fishing. This small family contains the Coryphaena hippurus and Coryphaena equiselis species whose chromosomal aspects remain unknown, despite recent advances in cytogenetic data assimilation for Perciformes. In this study, both species were cytogenetically analyzed using different staining techniques (C-, Ag-, and CMA3 banding) and fluorescence in situ hybridization, to detect 18S rDNA and 5S rDNA. C. hippurus females exhibit 2n = 48 chromosomes, with 2m+4sm+42a (NF = 54). In C. equiselis, where both sexes could be analyzed, females displayed 2n = 48 chromosomes (2m+6sm+40a) and males exhibited 2n = 47 chromosomes (3m+6sm+38a) (NF = 56), indicating the presence of X1X1X2X2/X1X2Y multiple sex chromosomes. Sex-chromosome systems are rare in Perciformes, with this study demonstrating the first occurrence in a marine pelagic species. It remains unknown as to whether this system extends to other populations; however, these data are important with respect to evolutionary, phylogenetic, and speciation issues, as well as for elucidating the genesis of this unique sex system.
鲯鳅（鲯鳅科）是分布于所有热带和亚热带海洋的远洋捕食者，对商业、传统和休闲渔业都非常重要。这个小科包含鲯鳅（Coryphaena hippurus）和长鳍鲯鳅（Coryphaena equiselis）两个物种，尽管鲈形目细胞遗传学数据同化方面最近取得了进展，但它们的染色体情况仍然未知。在本研究中，对这两个物种都使用了不同的染色技术（C带、Ag带和CMA3带）以及荧光原位杂交进行细胞遗传学分析，以检测18S rDNA和5S rDNA。鲯鳅雌性显示2n = 48条染色体，其中2m + 4sm + 42a（NF = 54）。在长鳍鲯鳅中，两性均能进行分析，雌性显示2n = 48条染色体（2m + 6sm + 40a），雄性显示2n = 47条染色体（3m + 6sm + 38a）（NF = 56），表明存在X1X1X2X2/X1X2Y多重性染色体。性染色体系统在鲈形目中很少见，本研究证明其首次出现在海洋远洋物种中。该系统是否扩展到其他种群仍然未知；然而，这些数据对于进化、系统发育和物种形成问题以及阐明这种独特性系统的起源都很重要。
