Degrandi Tiago M, Del Valle Garnero Analía, O'Brien Patricia C M, Ferguson-Smith Malcolm A, Kretschmer Rafael, de Oliveira Edivaldo H C, Gunski Ricardo J
Programa de Pós Graduação em Genética, Laboratório de Citogenética e Genética da Conservação Animal, Universidade Federal do Paraná, Curitiba, Brazil.
Cytogenet Genome Res. 2017;151(4):208-215. doi: 10.1159/000471782. Epub 2017 May 13.
Trogons are forest birds with a wide distribution, being found in Africa, Asia, and America, and are included in the order Trogoniformes, family Trogonidae. Phylogenetic studies using molecular data have not been able to determine the phylogenetic relationship among the different genera of trogons. So far, no cytogenetic data for these birds exist. Hence, the aim of this study was to characterize the karyotype of Trogon surrucura surrucura by means of classical and molecular cytogenetics. We found a diploid chromosome number of 2n = 82, similar to most birds, with several derived features compared to chicken and the putative ancestral avian karyotype. T. s. surrucura showed 3 pairs of microchromosomes bearing 18S rDNA clusters. The Z and W sex chromosomes were of similar size but could readily be identified by morphological differences. Using chromosome painting with whole chromosome probes from Gallus gallus and Leucopternis albicollis, we found that the chromosomes homologous to chicken chromosomes 2 and 5 correspond to 2 different pairs in T. s. surrucura and L. albicollis, due to the occurrence of centric fissions. Paracentric inversions were detected in the segment homologous to chicken chromosome 1q, and we confirmed the recurrence of breakpoints when our results were compared to other species of birds already analyzed by FISH or by in silico genome assembly.
咬鹃是一种分布广泛的森林鸟类，见于非洲、亚洲和美洲，属于咬鹃目咬鹃科。利用分子数据进行的系统发育研究未能确定不同咬鹃属之间的系统发育关系。到目前为止，尚无这些鸟类的细胞遗传学数据。因此，本研究的目的是通过经典和分子细胞遗传学方法对纯色咬鹃的核型进行特征描述。我们发现其二倍体染色体数为2n = 82，与大多数鸟类相似，与鸡和假定的鸟类祖先核型相比有一些衍生特征。纯色咬鹃显示有3对带有18S rDNA簇的微小染色体。Z和W性染色体大小相似，但可通过形态差异轻易识别。使用来自家鸡和白颈凤冠雉的全染色体探针进行染色体涂染，我们发现与鸡染色体2和5同源的染色体在纯色咬鹃和白颈凤冠雉中对应于2对不同的染色体，这是由于着丝粒裂变的发生。在与鸡染色体1q同源的片段中检测到臂内倒位，当我们将结果与已通过荧光原位杂交或电子基因组组装分析的其他鸟类物种进行比较时，我们证实了断点的重现性。
