Häger K P, Müller B, Wind C, Erbach S, Fischer H
University of Bayreuth, Department of Plant Ecology and Systematics, Germany.
FEBS Lett. 1996 May 27;387(1):94-8. doi: 10.1016/0014-5793(96)00477-2.
The polymerase chain reaction was used to survey gymnosperm legumin genes. Characterization of 46 cloned amplificates, differing in sequence and size (1.2-1.6 kb), revealed the ubiquitous occurrence of legumin genes and their organization in small subfamilies in the 22 species investigated. The 3' portions of the genes, coding for the legumin beta-polypeptides, show a highly conserved intron/exon structure divergent from those of angiosperms: an additional intron (intron IV) uniformly interrupts the region coding for the C-terminal part of the beta-polypeptides. Phylogenetic analysis of the respective coding sequences as well as the organization of the Magnolia B14 legumin gene also investigated here both indicate that intron IV is ancestral and was lost during early angiosperm evolution. Taking into account the intron/exon structures from all legumin genes known, our results suggest that legumin genes evolved by subsequent loss of introns, providing also further evidence for a common origin of legumins and vicilins.
采用聚合酶链反应来检测裸子植物豆球蛋白基因。对46个克隆扩增产物进行表征，这些产物在序列和大小（1.2 - 1.6 kb）上存在差异，结果显示在所研究的22个物种中，豆球蛋白基因普遍存在且以小亚家族形式组织存在。这些基因编码豆球蛋白β - 多肽的3'部分，呈现出与被子植物不同的高度保守的内含子/外显子结构：一个额外的内含子（内含子IV）一致地打断了编码β - 多肽C末端部分的区域。对各自编码序列的系统发育分析以及本文所研究的木兰B14豆球蛋白基因的组织情况均表明，内含子IV是祖先型的，并且在被子植物早期进化过程中丢失了。考虑到所有已知豆球蛋白基因的内含子/外显子结构，我们的结果表明豆球蛋白基因是通过随后内含子的丢失而进化的，这也为豆球蛋白和豌豆球蛋白的共同起源提供了进一步的证据。
