Stalder J, Wirthmüller U, Beck J, Gruber A, Meyerhof W, Knöchel W, Weber R
Zoologisches Institut, Abteilung für Zell- und Entwicklungsbiologie, Bern, Switzerland.
J Mol Evol. 1988;28(1-2):64-71. doi: 10.1007/BF02143498.
To investigate the evolution of globin genes in the genus Xenopus, we have determined the primary structure of the related adult alpha I- and alpha II-globin genes of X. laevis and of the adult alpha-globin gene of X. tropicalis, including their 5'-flanking regions. All three genes are comprised of three exons and two introns at homologous positions. The exons are highly conserved and code for 141 amino acids. By contrast, the corresponding introns vary in length and show considerable divergence. Comparison of 900 bp of the 5'-flanking region revealed that the X. tropicalis gene contains a conserved proximal 310-bp promoter sequence, comprised of the canonical TATA and CCAAT motifs at homologous positions, and five conserved elements in the same order and at similar positions as previously shown for the corresponding genes of X. laevis. We therefore conclude that these conserved upstream elements may represent regulatory sequences for cell-specific regulation of the adult Xenopus globin genes.
为了研究非洲爪蟾属中珠蛋白基因的进化，我们测定了非洲爪蟾相关的成年αI -和αII -珠蛋白基因以及热带爪蟾成年α -珠蛋白基因的一级结构，包括它们的5'侧翼区域。所有这三个基因都由三个外显子和两个位于同源位置的内含子组成。外显子高度保守，编码141个氨基酸。相比之下，相应的内含子长度不同且显示出相当大的差异。对900 bp的5'侧翼区域进行比较发现，热带爪蟾基因包含一个保守的近端310 bp启动子序列，该序列在同源位置由典型的TATA和CCAAT基序组成，并且有五个保守元件，其顺序和位置与先前在非洲爪蟾相应基因中显示的相同。因此，我们得出结论，这些保守的上游元件可能代表成年非洲爪蟾珠蛋白基因细胞特异性调控的调控序列。
