Inokuchi N
Department of Biochemistry and Molecular Biology, Nippon Medical School, Tokyo, Japan.
Nihon Ika Daigaku Zasshi. 1994 Nov;61(6):620-32. doi: 10.1272/jnms1923.61.620.
In order to clarify the molecular basis of the heterogeneity of rat hemoglobins, two DNA clones containing the genes for adult type beta-globins were isolated from a rat genomic DNA library. The results obtained in the present experiments are summarized as follows. 1) Clone lambda Rg beta 59 contained the gene for an adult rat beta-major globin, II beta, while clone lambda Rg beta 45 contained the genes for two adult rat beta-minor globins, III beta, and O beta, respectively. 2) The entire nucleotide sequences of these genes were determined, indicating that the genes are all composed of 3 exons and 2 introns, and code for 146 amino acid residues. The genes exhibited structural features typical to known expressed beta-like globin genes, implying that they are all functional. 3) The predicted amino acid sequences completely agreed with the amino acid sequences of II beta, III beta and O beta globins, respectively, which we isolated in a separate experiment. 4) Sequence comparisons of three rat globin genes with one another and with the known mouse beta-major and beta-minor globin genes showed the occurrence of interesting homologies between two species from evolutional aspects. 5) Southern hybridization analysis of the genomic DNA implies that a number of beta-like globin genes other than the present ones exist in the rat genome.
为了阐明大鼠血红蛋白异质性的分子基础，从大鼠基因组DNA文库中分离出两个包含成年型β - 珠蛋白基因的DNA克隆。本实验获得的结果总结如下。1）克隆λRgβ59包含成年大鼠β - 主要珠蛋白IIβ的基因，而克隆λRgβ45分别包含两种成年大鼠β - 次要珠蛋白IIIβ和Oβ的基因。2）测定了这些基因的完整核苷酸序列，表明这些基因均由3个外显子和2个内含子组成，并编码146个氨基酸残基。这些基因表现出已知表达的β - 样珠蛋白基因典型的结构特征，这意味着它们均具有功能。3）预测的氨基酸序列分别与我们在另一项实验中分离出的IIβ、IIIβ和Oβ珠蛋白的氨基酸序列完全一致。4）对三个大鼠珠蛋白基因彼此之间以及与已知的小鼠β - 主要和β - 次要珠蛋白基因进行序列比较，从进化角度显示了两个物种之间存在有趣的同源性。5）基因组DNA的Southern杂交分析表明，大鼠基因组中存在除当前这些基因之外的许多β - 样珠蛋白基因。
