Degrandi Tiago M, Barcellos Suziane A, Costa Alice L, Garnero Analía D V, Hass Iris, Gunski Ricardo J
Cytogenet Genome Res. 2020;160(4):199-205. doi: 10.1159/000507768. Epub 2020 May 6.
Bird chromosomes, which have been investigated scientifically for more than a century, present a number of unique features. In general, bird karyotypes have a high diploid number (2n) of typically around 80 chromosomes that are divided into macro- and microchromosomes. In recent decades, FISH studies using whole chromosome painting probes have shown that the macrochromosomes evolved through both inter- and intrachromosomal rearrangements. However, chromosome painting data are available for only a few bird species, which hinders a more systematic approach to the understanding of the evolutionary history of the enigmatic bird karyotype. Thus, we decided to create an innovative database through compilation of the cytogenetic data available for birds, including chromosome numbers and the results of chromosome painting with chicken (Gallus gallus) probes. The data were obtained through an extensive literature review, which focused on cytogenetic studies published up to 2019. In the first version of the "Bird Chromosome Database (BCD)" (https://sites.unipampa.edu.br/birdchromosomedatabase) we have compiled data on the chromosome numbers of 1,067 bird species and chromosome painting data on 96 species. We found considerable variation in the diploid numbers, which ranged from 40 to 142, although most (around 50%) of the species studied up to now have between 78 and 82 chromosomes. Despite its importance for cytogenetic research, chromosome painting has been applied to less than 1% of all bird species. The BCD will enable researchers to identify the main knowledge gaps in bird cytogenetics, including the most under-sampled groups, and make inferences on chromosomal homologies in phylogenetic studies.
鸟类染色体已经经过了一个多世纪的科学研究，呈现出许多独特的特征。一般来说，鸟类核型的二倍体数目（2n）很高，通常约为80条染色体，可分为大染色体和小染色体。近几十年来，使用全染色体涂染探针的荧光原位杂交（FISH）研究表明，大染色体是通过染色体间和染色体内的重排进化而来的。然而，只有少数鸟类物种有染色体涂染数据，这阻碍了我们采用更系统的方法来理解神秘的鸟类核型的进化历史。因此，我们决定通过汇编鸟类现有的细胞遗传学数据来创建一个创新的数据库，包括染色体数目以及用鸡（原鸡）探针进行染色体涂染的结果。这些数据是通过广泛的文献综述获得的，重点是截至2019年发表的细胞遗传学研究。在“鸟类染色体数据库（BCD）”（https://sites.unipampa.edu.br/birdchromosomedatabase）的第一版中，我们汇编了1067种鸟类的染色体数目数据和96种鸟类的染色体涂染数据。我们发现二倍体数目存在相当大的差异，范围从40到142，尽管到目前为止研究的大多数（约50%）物种的染色体数目在78到82条之间。尽管染色体涂染对细胞遗传学研究很重要，但它应用于所有鸟类物种的比例还不到1%。BCD将使研究人员能够识别鸟类细胞遗传学中的主要知识空白，包括采样最少的群体，并在系统发育研究中推断染色体同源性。
