Comparative analysis and evolutionary significance of the HMG1 gene in crucian carp,blunt snout bream,and their polyploid progeny  

作　　者：Dong Liu Zhen Liu Shaojun Liu Liangguo Liu Cuiping You Lin Chen Huan Zhong Yun Liu 

机构地区：[1]Key Laboratory of Protein Chemistry and Developmental Biology of State Ministry of China, College of Life Science, Hunan Normal University Changsha 410081, China

出　　处：《Progress in Natural Science:Materials International》2009年第12期1691-1697,共7页自然科学进展·国际材料（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.30725028);the National Basic Research Program of China(2007CB109200);Furong Scholars Fund of Hunan Province.

摘　　要：The full-length mRNA of the high mobility group protein 1 coding gene （HMG1） was obtained by RACE-PCR from red crucian carp （Carassius auratus red var.）, blunt snout bream （Megalobrama amblycephala）, and their triploid and tetraploid progeny. The sequence contained an open reading frame of 579 nucleotides coding for 193 amino acids. The nucleotide identity of HMG1 was higher between the tetraploid hybrid and the maternal red crucian carp （99%） than between the tetraploid hybrid and the paternal blunt snout bream （97%）. The nucleotide identity between the triploid hybrids and each parent （95%） was lower than that between the parents （98%）. The protein identity between the tetraploid hybrid and each parent （100%） was higher than that between the triploid hybrid and each parent （97%）. Our results suggest that interspecific hybridization generates a shock to the HMG1 gene in triploid hybrids, causing divergence of nucleotides. The HMG1 protein of the tetraploid hybrids was consistent with that of its parents, which reduced the barrier of cross incompatibility between alleles, providing the basis for the bisexual fertile tetraploid hybrids forming a new polyploid species in nature. The secondary and tertiary structures of the HMG1 protein contain eight helices, three switches, two DNA-binding domains in the N- terminus, and a long acidic tail in the C-terminus. Together, these data suggest that the HMG1 protein plays a role of protein-DNA interactions, facilitating various DNA-dependent activities in the nucleus. We also investigated the phylogeny of fish, amphibian, reptilian, bird, and mammalian HMG1 proteins. Our results suggest that HMG1 is an ancestral protein that has been highly conserved. These data provide clues as to how interspecific hybridization may form polyptoid hybrids.高活动性组蛋白质的全身的 mRNA 1 个编码基因(HMG1 ) 被 RACE-PCR 从红鲫鱼鲤鱼(Carassius auratus 红 var ) 获得，钝猪嘴鲷(Megalobrama amblycephala ) ，并且他们的三倍性并且 tetraploid 子孙。顺序包含了为 193 氨基酸编码的 579 核苷酸的一个开的读物框架。HMG1 的核苷酸身份比在 tetraploid 混血儿和父亲的钝猪嘴鲷(97%) 之间在 tetraploid 混血儿和母亲的红鲫鱼鲤鱼(99%) 之间是更高的。在三倍性的混血儿和每个父母(95%) 之间的核苷酸身份在父母(98%) 之间是比那低的。在 tetraploid 混血儿和每个父母(100%) 之间的蛋白质身份在三倍性的混血儿和每个父母(97%) 之间比那高。我们的结果建议种间的杂交在三倍性的混血儿产生震动到 HMG1 基因，引起核苷酸的分叉。tetraploid 混血儿的 HMG1 蛋白质与它的父母的一致，它减少了在等位基因之间的生气不兼容的障碍，提供形成在自然的新多倍体种的两性的肥沃的 tetraploid 混血儿的基础。HMG1 蛋白质的第二等、第三级的结构包含八他 lices，三个开关，在 N 终点的二个 DNA 有约束力的领域，和在 C 终点的一条长酸的尾巴。一起，这些数据建议 HMG1 蛋白质起蛋白质 DNA 相互作用的一个作用，在原子核便于各种各样的 DNA 依赖的活动。我们也调查了鱼，两栖动物，爬虫，鸟，和哺乳动物的 HMG1 蛋白质的发展史。我们的结果建议 HMG1 是高度被保存了的祖先的蛋白质。这些数据提供种间的杂交怎么可以形成多倍体混血儿的线索。

关 键 词：Fish POLYPLOIDY High mobility protein coding gene Phylogeny Evolution 

分 类 号：S965.119[农业科学—水产养殖] Q943[农业科学—水产科学]