Roehrdanz R, Heilmann L, Senechal P, Sears S, Evenson P
Biosciences Research Laboratory, Red River Valley Agricultural Research Center, Agricultural Research Service, U.S. Department of Agriculture, Fargo, ND 58105, USA.
Insect Mol Biol. 2010 Aug;19(4):463-71. doi: 10.1111/j.1365-2583.2010.01006.x. Epub 2010 May 1.
Histones are the major protein component of chromatin structure. The histone family is made up of a quintet of proteins, four core histones (H2A, H2B, H3 & H4) and the linker histones (H1). Spacers are found between the coding regions. Among insects this quintet of genes is usually clustered and the clusters are tandemly repeated. Ribosomal DNA contains a cluster of the rRNA sequences 18S, 5.8S and 28S. The rRNA genes are separated by the spacers ITS1, ITS2 and IGS. This cluster is also tandemly repeated. We found that the ribosomal RNA repeat unit of at least two species of Anthonomine weevils, Anthonomus grandis and Anthonomus texanus (Coleoptera: Curculionidae), is interspersed with a block containing the histone gene quintet. The histone genes are situated between the rRNA 18S and 28S genes in what is known as the intergenic spacer region (IGS). The complete reiterated Anthonomus grandis histone-ribosomal sequence is 16,248 bp.
组蛋白是染色质结构的主要蛋白质成分。组蛋白家族由一组五种蛋白质组成，四种核心组蛋白（H2A、H2B、H3和H4）以及连接组蛋白（H1）。在编码区域之间发现有间隔序列。在昆虫中，这一组五个基因通常成簇存在，并且这些簇是串联重复的。核糖体DNA包含18S、5.8S和28S的rRNA序列簇。rRNA基因被间隔序列ITS1、ITS2和IGS隔开。这个簇也是串联重复的。我们发现，至少两种花象鼻虫，即棉铃象甲和德克萨斯象甲（鞘翅目：象甲科）的核糖体RNA重复单元中散布着一个包含组蛋白基因五重奏的片段。组蛋白基因位于rRNA的18S和28S基因之间的所谓基因间隔区（IGS）。棉铃象甲完整的重复组蛋白-核糖体序列为16,248碱基对。
