Forget B G
Tex Rep Biol Med. 1980;40:77-86.
A very precise picture of the fine structure and organization of the human globin genes has recently emerged from the study of cloned fragments of chromosomal DNA containing the globin genes and their flanking DNA. The precise sizes, locations and nucleotide sequences of intervening sequences (introns) that interrupt the globin genes have been determined. A number of presumably functionally important preserved nucleotide sequences common to all of the globin genes have been identified within the 5'-flanking DNA of the genes, as well as in their untranslated sequences and at the junctions between coding and intervening sequences. Intergene distances as well as the sizes of duplication units of closely related genes have been determined. A somewhat unexpected finding has been the identification of apparently nonexpressed globin pseudogenes within the globin gene clusters. Finally, detailed analysis of intergene DNA has revealed the presence of different types of repetitive DNA sequences in the vicinity of many of the globin genes but the significance of this finding with regard to the control of globin gene expression is not yet known.
最近,通过对包含珠蛋白基因及其侧翼DNA的染色体DNA克隆片段的研究,已形成了一幅关于人类珠蛋白基因精细结构和组织的精确图谱。中断珠蛋白基因的间隔序列(内含子)的精确大小、位置和核苷酸序列已被确定。在基因的5'侧翼DNA内,以及在它们的非翻译序列中,和编码与间隔序列之间的连接处,已鉴定出许多所有珠蛋白基因共有的、可能具有功能重要性的保守核苷酸序列。基因间距离以及密切相关基因的重复单位大小也已确定。一个有点意外的发现是在珠蛋白基因簇中鉴定出了明显不表达的珠蛋白假基因。最后,对基因间DNA的详细分析揭示了许多珠蛋白基因附近存在不同类型的重复DNA序列,但这一发现对于珠蛋白基因表达调控的意义尚不清楚。