Institute of Molecular and Cellular Biology, SB RAS, 630090 Novosibirsk, Russia.
Novosibirsk State University, 630090, Novosibirsk, Russia.
Genes (Basel). 2019 Oct 29;10(11):857. doi: 10.3390/genes10110857.
Bovidae, the largest family in Pecora infraorder, are characterized by a striking variability in diploid number of chromosomes between species and among individuals within a species. The bovid X chromosome is also remarkably variable, with several morphological types in the family. Here we built a detailed chromosome map of musk ox (), a relic species originating from Pleistocene megafauna, with dromedary and human probes using chromosome painting. We trace chromosomal rearrangements during Bovidae evolution by comparing species already studied by chromosome painting. The musk ox karyotype differs from the ancestral pecoran karyotype by six fusions, one fission, and three inversions. We discuss changes in pecoran ancestral karyotype in the light of new painting data. Variations in the X chromosome structure of four bovid species nilgai bull (), saola (), gaur (), and Kirk's Dikdik () were further analyzed using 26 cattle BAC-clones. We found the duplication on the X in saola. We show main rearrangements leading to the formation of four types of bovid X: Bovinae type with derived cattle subtype formed by centromere reposition and Antilopinae type with Caprini subtype formed by inversion in XSB3.
牛科是偶蹄目反刍亚目下的一个大科，其物种间和同一物种内个体间的染色体二倍体数目存在显著差异。牛科的 X 染色体也非常多样化，在该科中有几种形态类型。在这里，我们使用染色体涂染技术，利用骆驼和人类的探针，为麝香牛（）构建了详细的染色体图谱。麝香牛是一种来自更新世巨型动物群的遗迹物种，我们通过比较已经通过染色体涂染研究过的物种来追踪牛科进化过程中的染色体重排。麝香牛的核型与祖先反刍动物的核型相比有六个融合、一个裂变和三个倒位。我们根据新的涂染数据讨论了反刍动物祖先核型的变化。我们进一步分析了四种牛科物种（印度野牛、越南野牛、白肢野牛和跳羚）的 X 染色体结构的变异，使用了 26 个牛 BAC 克隆。我们在 saola 中发现了 X 上的重复。我们展示了导致四种牛科 X 类型形成的主要重排：由着丝粒重定位形成的 Bovinae 类型和由 XSB3 内倒位形成的 Caprini 亚型的 Antilopinae 类型。
