MOLECULAR CHARACTERIZATION OF THE HISTONE GENE FAMILY OF CAENORHABDITIS-ELEGANS
MOLECULAR CHARACTERIZATION OF THE HISTONE GENE FAMILY OF CAENORHABDITIS-ELEGANS
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DOI：
10.1016/0022-2836(87)90508-0
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发表时间：
1987-07-05
影响因子：
5.6
通讯作者：
CHILDS, G
中科院分区：
文献类型：
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作者：
ROBERTS, SB;SANICOLA, M;CHILDS, G
秀丽线虫的核心组蛋白基因(H_2A、H_2B、H_3和H_4)分布在大约11个分散的簇中，并不是成串排列在基因组中。三个特征良好的基因组克隆包含组蛋白基因，每个簇都有每个核心组蛋白基因的一个副本。其中一个克隆(λCeh-1)携带一个被几千个碱基对的非组蛋白DNA包围的组蛋白簇，而另一个克隆(λCeh-3)包含被非组蛋白DNA包围的组蛋白簇复制。第三个克隆(lambda.Ceh-2)携带一组核心组蛋白基因，在一侧(12,000个碱基对)两侧是单一的H_2B基因，另一侧是非组蛋白DNA。第四个簇(克隆BE9)具有H3和H4各一个拷贝以及H2 A和H2 B各两个拷贝。这个簇的两侧也有非组蛋白DNA。对与其中三个簇重叠的粘粒克隆的分析表明，没有其他组蛋白簇比8000到60,000个碱基对更近，尽管侧翼区域存在未知的非组蛋白转录单位。组蛋白簇中的基因顺序不同，组蛋白mRNAs从两条DNA链转录而来。在这些核心组蛋白克隆上没有发现H1序列。利用两个相关线虫菌株(Bristol和Bergerac)之间的限制性片段长度多态性作为遗传杂交的表型标记，将一个组蛋白簇定位到连锁组V，将另一个组蛋白簇定位到连锁组IV。从血清海胆到线虫RNA的基因特异性探针杂交发现，线虫核心组蛋白信使RNA的大小与血清海胆早期组蛋白mRNAs(H_2A、H_2B、H_3和H_4)相似。线虫中组蛋白基因的组织类似于大多数脊椎动物中发现的聚集性，而不像海胆早期组蛋白基因家族的串联模式或果蝇的主要组蛋白基因位点。
The core histone genes (H2A, H2B, H3 and H4) of Caenorhabditis elegans are arranged in approximately 11 dispersed clusters and are not tandemly arrayed in the genome. Three well-characterized genomic clones, which contain histone genes, have one copy of each core histone gene per cluster. One of the clones (.lambda.Ceh-1) carried one histone cluster surrounded by several thousand base-pairs of non-histone DNA, and another clone (.lambda.Ceh-3) contains a histone cluster duplication surrounded by non-histone DNA. A third clone (.lambda.Ceh-2) carries a cluster of core histone genes flanked on one side (12,000 base-pairs away) by a single H2B gene and on the other by non-histone DNA. A fourth cluster (clone BE9) has one copy each of H3 and H4 and two copies each of H2A and H2B. This cluster is also flanked by non-histone DNA. Analysis of cosmid clones which overlap three of the clusters shows that no other histone clusters are closer than 8000 to 60,000 base pairs, although unidentified non-histone transcription units are present on the flanking regions. Gene order within the histone clusters varies, and histone mRNAs are transcribed from both DNA strands. No H1 sequences are found on these core histone clones. Restriction fragment length polymorphisms between two related nematode strains (Bristol and Bergerac) were used as phenotypic markers in genetic crosses to map one histone cluster to linkage group V and another to linkage group IV. Hybridization of gene-specific probes from sera urchin to C. elegans RNA identifies C. elegans core histone messenger RNAs of sizes similar to sera urchin early stage histone mRNAs (H2A, H2B, H3 and H4). The organization of histone genes in C. elegans resembles the clustering found in most vertebrate organisms and does not resemble the tandem patterns of the early stage histone gene family of sea urchins or the major histone locus of Drosophila.