Data from: Copy number polymorphism in the α-globin gene cluster of European rabbit (Oryctolagus cuniculus).

Comparative genomic studies have revealed that mammals typically possess two or more tandemly duplicated copies of the α-globin (HBA) gene. The domestic rabbit represents an exception to this general rule, as this species was found to possess a single HBA gene. Previous electrophoretic surveys of HBA polymorphism in natural populations of the European rabbit (Oryctolagus cuniculus) revealed extensive geographic variation in the frequencies of three main electromorphs. The variation in frequency of two electromorphs is mainly partitioned between two distinct subspecies of European rabbit, and a third is restricted to the hybrid zone between the two rabbit subspecies in Iberia. Here we report the results of a survey of nucleotide polymorphism which revealed HBA copy number polymorphism in Iberian populations of the European rabbit. By characterizing patterns of HBA polymorphism in populations from the native range of the European rabbit we were able to identify the specific amino acid substitutions that distinguish the previously characterized electromorphs. Within the hybrid zone, we observed the existence of a second HBA gene duplicate, named HBA2, that mostly represents a novel sequence haplotype which occurs in higher frequency within the hybrid zone and thus appears to have arisen in hybrids of the two distinct subspecies. While this novel gene is also present in other wild Iberian populations, it is almost absent from French populations which suggest a recent ancestry, associated with the establishment of the post-Pleistocene contact zone between the two European rabbit subspecies.

比较基因组学研究表明，哺乳动物通常拥有2个或更多串联重复的α-珠蛋白（α-globin, HBA）基因拷贝。家兔则是这一普遍规律的例外，该物种仅携带1个HBA基因。此前针对欧洲兔（Oryctolagus cuniculus）自然种群中HBA多态性的电泳调查显示，三种主要电泳型的频率存在广泛的地理差异。其中两种电泳型的频率差异主要分布于两个不同的欧洲兔亚种之间，而第三种电泳型仅局限于伊比利亚半岛两个兔亚种间的杂交带内。本研究报告了一项核苷酸多态性调查的结果，该调查在欧洲兔的伊比利亚种群中发现了HBA基因的拷贝数多态性。通过对欧洲兔原生分布区种群的HBA多态性模式进行解析，我们得以确定区分此前已鉴定电泳型的特异性氨基酸替换位点。在该杂交带内，我们发现了第二个HBA基因拷贝，命名为HBA2，其大多携带新型序列单倍型，且在杂交带内的频率更高，因此该基因似乎起源于两个不同亚种的杂交后代。尽管该新型基因也存在于其他伊比利亚野生种群中，但在法国种群中几乎未被检出，这表明其起源较晚，与更新世后两个欧洲兔亚种接触带的形成密切相关。