Department of Genetics, University of Wisconsin, Madison, WI 53706, USA.
Genetics. 2012 Jul;191(3):951-8. doi: 10.1534/genetics.112.138479. Epub 2012 Apr 13.
Despite numerous quantitative trait loci and association mapping studies, our understanding of the extent to which natural allelic series contribute to the variation for complex traits is limited. In this study, we investigate the occurrence of a natural allelic series for complex traits at the teosinte branched1 (tb1) gene in natural populations of teosinte (Zea mays ssp. parviglumis, Z. mays ssp. mexicana, and Z. diploperennis). Previously, tb1 was shown to confer large effects on both plant architecture and ear morphology between domesticated maize and teosinte; however, the effect of tb1 on trait variation in natural populations of teosinte has not been investigated. We compare the effects of nine teosinte alleles of tb1 that were introgressed into an isogenic maize inbred background. Our results provide evidence for a natural allelic series at tb1 for several complex morphological traits. The teosinte introgressions separate into three distinct phenotypic classes, which correspond to the taxonomic origin of the alleles. The effects of the three allelic classes also correspond to known morphological differences between the teosinte taxa. Our results suggest that tb1 contributed to the morphological diversification of teosinte taxa as well as to the domestication of maize.
尽管进行了大量的数量性状位点和关联图谱研究，但我们对于自然等位基因系列在多大程度上导致复杂性状变异的理解是有限的。在这项研究中，我们调查了在天然的玉米近缘植物大刍草（Zea mays ssp. parviglumis、Zea mays ssp. mexicana 和 Zea diploperennis）中，分支 1 基因（teosinte branched1，tb1）的自然等位基因系列对复杂性状发生的情况。先前的研究表明，tb1 在驯化玉米和大刍草之间的植物结构和穗部形态上都有很大的影响；然而，tb1 对大刍草天然种群中性状变异的影响尚未被研究。我们比较了九个导入到同基因玉米自交系背景中的大刍草 tb1 等位基因的效应。我们的结果为 tb1 对几个复杂形态性状存在自然等位基因系列提供了证据。大刍草的导入物分离为三个不同的表型类群，与等位基因的分类学起源相对应。这三个等位基因类群的效应也与大刍草分类群之间已知的形态差异相对应。我们的结果表明，tb1 促进了大刍草分类群的形态多样化以及玉米的驯化。
