Dolgushin K V, Petrova N V, Iudinkova E S, Razin S V, Iarovaia O V
Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334 Russia.
Biology Department, Moscow State University, Moscow, 119991 Russia.
Mol Biol (Mosk). 2015 May-Jun;49(3):498-506. doi: 10.7868/S0026898415030040.
In the domain model of eukaryotic genome organization, the functional unit of the genome, along with the relevant regulatory elements, is considered to be a gene or a gene family. In hot-blooded vertebrate animals, the domains of a- and b-globin genes are positioned at different chromosomes and are organized and regulated in different fashion. In cold-blooded animals, in particular in tropical fish Danio rerio, a- and b globin genes are located in a common gene cluster. However, the joint a/b-globin gene cluster is subdivided into two development stage-specific subdomains, the adult one and the embryonic-larval one. In an attempt to find out whether this functional segregation correlates with structural segregation of the domain we compared the DNase I sensitivity and profiles of histone modifications of adult and embryonic-larval segments of the domain in cultured D. rerio fibroblasts. We have demonstrated that, in these nonerythroid cells, adult and embryonic- larval subdomains possess different DNase I sensitivities and different profiles of H3K27me3, a histone modification introduced by PRC2 complex. These observations suggest that joint a/b globin gene domain of Danio rerio is segregated into two structural subdomain harboring adult and embryonic-larval globin genes.
在真核生物基因组组织的结构模型中，基因组的功能单元以及相关调控元件被认为是一个基因或一个基因家族。在热血脊椎动物中，α-和β-珠蛋白基因的结构域位于不同的染色体上，并以不同的方式进行组织和调控。在冷血动物中，特别是在热带鱼斑马鱼中，α-和β-珠蛋白基因位于一个共同的基因簇中。然而，联合的α/β-珠蛋白基因簇被细分为两个特定发育阶段的亚结构域，即成年亚结构域和胚胎-幼虫亚结构域。为了探究这种功能分离是否与该结构域的结构分离相关，我们比较了培养的斑马鱼成纤维细胞中该结构域成年和胚胎-幼虫片段的DNA酶I敏感性和组蛋白修饰谱。我们已经证明，在这些非红细胞系细胞中，成年和胚胎-幼虫亚结构域具有不同的DNA酶I敏感性和不同的H3K27me3组蛋白修饰谱，H3K27me3是由PRC2复合物引入的一种组蛋白修饰。这些观察结果表明，斑马鱼的联合α/β珠蛋白基因结构域被分离成两个结构亚结构域，分别包含成年和胚胎-幼虫珠蛋白基因。
