Padgett R W, Loeb D D, Snyder L R, Edgell M H, Hutchison C A
Department of Microbiology and Immunology, University of North Carolina, Chapel Hill 27514.
Mol Biol Evol. 1987 Jan;4(1):30-45. doi: 10.1093/oxfordjournals.molbev.a040425.
Recombinant DNA clones have been isolated that contain 80 kb of the beta-globin complex from the deer mouse, Peromyscus maniculatus. Comparisons of this complex with that from the laboratory mouse, Mus domesticus (with an order 5'-Hbby, Hbb-bhO, Hbb-bhl, Hbb-bh2, Hbb-bh3, Hbb-bl, Hbb-b2 3') highlight organizational trends in the beta-globin complex since the two species diverged. Unlike other mammals studied thus far, the deer mouse possesses three adult genes. Partial sequence analysis indicates that each of the three adult genes is intact and hence may be functional. Hybridization of one of the two Mus pseudogenes, Hbb-bh3, to genomic blots from Peromyscus reveals that it has a homologous counterpart in Peromyscus. Homologous genes to the two gamma-like Mus genes, Hbb-bhO and Hbb-bhl, are also found in Peromyscus. The strong hybridization between the Hbb-bhl genes and significant nucleotide similarity between the Hbb-bhO genes suggest that both pairs are important for the ontogeny of these mice although no known product has been identified for the Hbb-bhO genes. The presence of Hbb-bhO and Hbb-bhl in Peromyscus suggests that the duplication that created this related gene set occurred before the two lineages diverged. A single gene for Hbb-y has been isolated from Peromyscus. The adult region in Peromyscus has undergone significant divergence from the same region in Mus, having three rather than two adult genes, the acquisition of at least 15 kb of extra DNA relative to Mus, and possibly the loss of the Hbb-bh2 pseudogene. The nonadult region of the complex, in contrast, contains the same set of genes apparently distributed over the same amount of DNA as in the Mus beta-globin complex. This observation suggests that the embryonic region of the complex is more evolutionarily stable than the adult region.
已分离出重组DNA克隆，其包含来自鹿鼠（白足鼠）β-珠蛋白复合体的80kb片段。将该复合体与实验室小鼠（小家鼠）的β-珠蛋白复合体（顺序为5'-Hbby、Hbb-bhO、Hbb-bhl、Hbb-bh2、Hbb-bh3、Hbb-bl、Hbb-b2 3'）进行比较，突出了自这两个物种分化以来β-珠蛋白复合体的组织趋势。与迄今为止研究的其他哺乳动物不同，鹿鼠拥有三个成年基因。部分序列分析表明，这三个成年基因中的每一个都是完整的，因此可能具有功能。小家鼠的两个假基因之一Hbb-bh3与鹿鼠的基因组印迹杂交，表明它在鹿鼠中有一个同源对应物。在鹿鼠中也发现了与小家鼠的两个类γ基因Hbb-bhO和Hbb-bhl同源的基因。Hbb-bhl基因之间的强杂交以及Hbb-bhO基因之间显著的核苷酸相似性表明，这两对基因对这些小鼠的个体发育都很重要，尽管尚未确定Hbb-bhO基因的已知产物。鹿鼠中存在Hbb-bhO和Hbb-bhl表明，产生这个相关基因集的复制发生在这两个谱系分化之前。已从鹿鼠中分离出一个Hbb-y基因。鹿鼠的成年区域与小家鼠的同一区域相比发生了显著分化，有三个而不是两个成年基因，相对于小家鼠获得了至少15kb的额外DNA，并且可能失去了Hbb-bh2假基因。相比之下，该复合体的非成年区域包含相同的基因集，这些基因显然分布在与小家鼠β-珠蛋白复合体相同数量的DNA上。这一观察结果表明，该复合体的胚胎区域比成年区域在进化上更稳定。
