Kretschmer Rafael, Souza Marcelo Santos de, Barcellos Suziane Alves, Degrandi Tiago Marafiga, Pereira Jorge C, O'Brien Patricia C M, Ferguson-Smith Malcolm A, Gunski Ricardo José, Garnero Analía Del Valle, Oliveira Edivaldo Herculano Correa de, Freitas Thales Renato Ochotorena de
Universidade Federal do Rio Grande do Sul, Programa de Pós-graduação em Genética e Biologia Molecular - PPGBM, Porto Alegre, Rio Grande do Sul, RS, Brazil.
University of Cambridge, Department of Veterinary Medicine, Cambridge Resource Centre for Comparative Genomics, Cambridge, United Kingdom.
Genet Mol Biol. 2020 Feb 17;43(1):e20190236. doi: 10.1590/1678-4685-GMB-2019-0236. eCollection 2020.
The order Charadriiformes comprises three major clades: Lari and Scolopaci as sister group to Charadrii. Until now, only three Charadriiformes species have been studied by chromosome painting: Larus argentatus (Lari), Burhinus oedicnemus and Vanellus chilensis (Charadrii). Hence, there is a lack of information concerning the third clade, Scolapaci. Based on this, and to gain a better understanding of karyotype evolution in the order Charadriiformes, we applied conventional and molecular cytogenetic approaches in a species belonging to clade Scolopaci - the wattled jacana (Jacana jacana) - using Gallus gallus and Zenaida auriculata chromosome-specific probes. Cross-species evaluation of J. jacana chromosomes shows extensive genomic reshuffling within macrochromosomes during evolution, with multiple fission and fusion events, although the diploid number remains at high level (2n=82). Interestingly, this species does not have the GGA7-8 fusion, which was found in two representatives of Charadrii clade, reinforcing the idea that this fusion may be exclusive to the Charadrii clade. In addition, it is shown that the chromosome evolution in Charadriiformes is complex and resulted in species with typical and atypical karyotypes. The karyotypic features of Scolopaci are very different from those of Charadrii and Lari, indicating that after divergence, each suborder has undergone different chromosome rearrangements.
鸥亚目和鹬亚目作为鸻亚目的姐妹群。到目前为止，只有三种鸻形目物种通过染色体涂染进行了研究：银鸥（鸥亚目）、石鸻和智利麦鸡（鸻亚目）。因此，关于第三个分支鹬亚目缺乏相关信息。基于此，为了更好地了解鸻形目的核型进化，我们使用家鸡和斑颊哀鸽染色体特异性探针，对属于鹬亚目的一种物种——肉垂水雉（水雉）——应用了传统和分子细胞遗传学方法。对水雉染色体的跨物种评估显示，在进化过程中，大型染色体内部发生了广泛的基因组重排，有多次裂变和融合事件，尽管二倍体数保持在较高水平（2n = 82）。有趣的是，该物种没有在家鸡7号和8号染色体融合现象，这种现象在鸻亚目的两个代表物种中被发现，这强化了这种融合可能是鸻亚目所特有的观点。此外，研究表明鸻形目的染色体进化是复杂的，导致了具有典型和非典型核型的物种。鹬亚目的核型特征与鸻亚目和鸥亚目的核型特征非常不同，这表明在分化之后，每个亚目都经历了不同的染色体重排。
