Natural alleles at a tomato fruit size quantitative trait locus differ by heterochronic regulatory mutations
Natural alleles at a tomato fruit size quantitative trait locus differ by heterochronic regulatory mutations
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DOI：
10.1073/pnas.172520999
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发表时间：
2002-10-15
影响因子：
11.1
通讯作者：
Tanksley, SD
中科院分区：
文献类型：
--
作者：
Cong, B;Liu, JP;Tanksley, SD
fw2.2是一个主要的数量性状基因座，其占野生番茄和栽培番茄之间果实大小差异的30%。迄今为止的证据表明，fw2.2等位基因通过基因调控的变化而不是FW2.2蛋白本身来调节果实大小。为了调查这些监管变化的性质和方式，他们可能会影响水果的大小，一对近等基因系进行了详细的发育，转录，有丝分裂，原位杂交研究。结果表明，fw2.2的大果型和小果型等位基因的峰值转录水平相差约1周。此外，这种表达时间的差异与果实发育早期有丝分裂活性的伴随变化有关。基因表达时间的变化（异时等位基因变异），结合总转录水平的总体差异，足以解释与两个等位基因相关的果实重量的大部分表型差异。
fw2.2 is a major quantitative trait locus that accounts for as much as 30% of the difference in fruit size between wild and cultivated tomatoes. Evidence thus far indicates that fw2.2 alleles modulate fruit size through changes in gene regulation rather than in the FW2.2 protein itself. To investigate the nature of these regulatory changes and the manner in which they may affect fruit size, a pair of nearly isogenic lines has been subjected to detailed developmental, transcriptional, mitotic, and in situ hybridization studies. The results indicate that the large- and small-fruited alleles of fw2.2 differ in peak transcript levels by approximate to1 week. Moreover, this difference in timing of expression is associated with concomitant changes in mitotic activity in the early stage of fruit development. The changes in timing of gene expression (heterochronic allelic variation), combined with overall differences in total transcript levels, are sufficient to account for a large portion phenotypic differences in fruit weight associated with the two alleles.