Abstract：
The genome organization of woodpeckers has several distinctive features e.g., an uncommon accumulation of repetitive sequences, enlarged Z chromosomes, and atypical diploid numbers. Despite the large diversity of species, there is a paucity of detailed cytogenomic studies for this group and we thus aimed to rectify this. Genome organization patterns and hence evolutionary change in the microchromosome formation of four species (Colaptes campestris, Veniliornis spilogaster, Melanerpes candidus, and Picumnus nebulosus) was established through fluorescence in situ hybridization using bacterial artificial chromosomes originally derived from Gallus gallus and Taeniopygia guttata. Findings suggest that P. nebulosus (2n = 110), which was described for the first time, had the most basal karyotype among species of Picidae studied here, and probably arose as a result of fissions of avian ancestral macrochromosomes. We defined a new chromosomal number for V. spilogaster (2n = 88) and demonstrated microchromosomal rearrangements involving C. campestris plus a single, unique hitherto undescribed rearrangement in V. spilogaster. This comprised an inversion after a fusion involving the ancestral microchromosome 12 (homologous to chicken microchromosome 12). We also determined that the low diploid number of M. candidus is related to microchromosome fusions. Woodpeckers thus exhibit significantly rearranged karyotypes compared to the putative ancestral karyotype.
摘要：
啄木鸟的基因组组织具有几个独特的特征，例如，重复序列的罕见积累，扩大的Z染色体，和非典型二倍体数。尽管物种多样性很大，对这一群体的详细细胞基因组研究很少，因此我们旨在纠正这一点。基因组组织模式以及四个物种微染色体形成的进化变化（Colaptescampestris，威尼奥斯斯波罗斯特，黑色素瘤念珠菌,和Picumnusnebulosus）是通过使用最初来自Gallusgallus和Taeniopygiaguttata的细菌人工染色体进行荧光原位杂交而建立的。研究结果表明，网状芽胞杆菌(2n=110)，这是第一次描述，在这里研究的Picidae物种中具有最基本的核型，可能是由于鸟类祖先大染色体的裂变而产生的。我们为V.spilogaster（2n=88）定义了一个新的染色体编号，并证明了涉及C.campestris的微染色体重排加上一个，在V.spliogaster中迄今未描述的独特重排。这包括涉及祖先微染色体12（与鸡微染色体12同源）的融合后的倒置。我们还确定，念珠菌的二倍体数低与微染色体融合有关。因此，与推定的祖先核型相比，啄木鸟表现出明显的重排核型。
