Drabent B, Louroutziatis A, Prats E, Cornudella L, Doenecke D
Institut für Biochemie und Molekulare Zellbiologie, Georg-August-Universität, Humboldtallee 23, Göttingen.
DNA Seq. 1995;6(1):41-5. doi: 10.3109/10425179509074698.
A genomic library of the sea cucumber Holothuria tubulosa was screened with human and murine histone gene hybridization probes. A recombinant phage carrying an H4 gene was isolated and sequenced. Hybridization analysis of the entire 20 kb phage insert with probes for H1, H2A, H2B and H3 histones was negative except for H2B. This solitary arrangement of the two neighbouring histone H4 and H2B genes is in contrast to the organization of 'cleavage stage' histone genes, which are arranged in tandem quintets of genes encoding the 5 histone classes. Gene organization and sequence features indicate that the two Holothuria genes are the equivalents of a known pair of late H2B and H4 genes which have been described in the genome of sea urchins. This result shows that the simultaneous occurrence of tandem repeats of histone gene quintets and smaller groups of structurally distinct histone gene subtypes is not unique for sea urchins, but also applies to other echinodermata, such as the sea cucumber Holothuria tubulosa.
用人和鼠的组蛋白基因杂交探针筛选了管足海参的基因组文库。分离出一个携带H4基因的重组噬菌体并进行了测序。用H1、H2A、H2B和H3组蛋白的探针，对整个20 kb的噬菌体插入片段进行杂交分析，除H2B外均为阴性。相邻的两个组蛋白H4和H2B基因的这种单独排列，与“卵裂期”组蛋白基因的组织方式形成对比，后者是由编码5种组蛋白类别的基因串联五联体排列而成。基因组织和序列特征表明，这两个海参基因相当于海胆基因组中已描述的一对已知的晚期H2B和H4基因。这一结果表明，组蛋白基因五联体串联重复与结构不同的组蛋白基因亚型较小群体的同时出现，并非海胆所特有，也适用于其他棘皮动物，如管足海参。
