Institute of Gene Biology Russian Academy of Sciences, Moscow, Russia.
Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia.
Mol Biol Evol. 2017 Jun 1;34(6):1492-1504. doi: 10.1093/molbev/msx100.
The genomes are folded in a complex three-dimensional (3D) structure. Some features of this organization are common for all eukaryotes, but little is known about its evolution. Here, we have studied the 3D organization and regulation of zebrafish globin gene domain and compared its organization and regulation with those of other vertebrate species. In birds and mammals, the α- and β-globin genes are segregated into separate clusters located on different chromosomes and organized into chromatin domains of different types, whereas in cold-blooded vertebrates, including Danio rerio, α- and β-globin genes are organized into common clusters. The major globin gene locus of Danio rerio is of particular interest as it is located in a genomic area that is syntenic in vertebrates and is controlled by a conserved enhancer. We have found that the major globin gene locus of Danio rerio is structurally and functionally segregated into two spatially distinct subloci harboring either adult or embryo-larval globin genes. These subloci demonstrate different organization at the level of chromatin domains and different modes of spatial organization, which appears to be due to selective interaction of the upstream enhancer with the sublocus harboring globin genes of the adult type. These data are discussed in terms of evolution of linear and 3D organization of gene clusters in vertebrates.
基因组以复杂的三维（3D）结构折叠。这种组织的某些特征在所有真核生物中都是共同的，但对其进化知之甚少。在这里，我们研究了斑马鱼珠蛋白基因结构域的三维组织和调控，并将其与其他脊椎动物物种的组织和调控进行了比较。在鸟类和哺乳动物中，α-和β-珠蛋白基因被分离到位于不同染色体上的不同簇中，并组织成不同类型的染色质域，而在冷血脊椎动物中，包括斑马鱼，α-和β-珠蛋白基因被组织成共同的簇。斑马鱼主要珠蛋白基因座特别有趣，因为它位于脊椎动物中具有同线性的基因组区域，并受保守增强子的控制。我们发现，斑马鱼的主要珠蛋白基因座在结构和功能上分为两个空间上不同的亚区，分别含有成体或胚胎-幼虫珠蛋白基因。这些亚区在染色质域的水平上表现出不同的组织，以及不同的空间组织模式，这似乎是由于上游增强子与含有成体类型珠蛋白基因的亚区选择性相互作用所致。这些数据是根据脊椎动物基因簇的线性和 3D 组织进化来讨论的。
