Beck D L, Dawson W O
Department of Plant Pathology, University of California, Riverside 92521.
Virology. 1990 Aug;177(2):462-9. doi: 10.1016/0042-6822(90)90510-x.
Tobacco mosaic virus (TMV) hybrids were constructed in vitro with an extra coat protein gene (gene order 5'- 126K/183K gene-30K gene-first coat protein gene-subgenomic mRNA promoter:second coat protein gene-3'). One coat protein gene was wild type and the other was derived from one of three coat protein mutants that elicit distinctive phenotypic responses. The hybrids contained large sequence repeats (up to 747 nucleotides). RNA transcripts of each of seven hybrid constructs initiated infections in host plants, but the progeny virus contained only one coat protein gene with no additional or missing nucleotides. Progeny of mutants with the two functional coat protein genes in different order within the genome retained coat protein gene sequence predicted by the number of repeated nucleotides 3' and 5' of the differential nucleotides. In contrast, progeny that resulted from virus hybrids with a wild-type and a nonfunctional coat protein gene possessed only the wild-type coat protein gene, even when the predicted progeny was a free-RNA virus. This demonstrated that selection strongly affected which progeny became predominant in the resulting populations.
烟草花叶病毒（TMV）杂种是在体外构建的，带有一个额外的外壳蛋白基因（基因顺序为5'-126K/183K基因-30K基因-第一个外壳蛋白基因-亚基因组mRNA启动子：第二个外壳蛋白基因-3'）。一个外壳蛋白基因是野生型的，另一个来自三种能引发独特表型反应的外壳蛋白突变体之一。这些杂种包含大的序列重复（长达747个核苷酸）。七个杂种构建体中的每一个的RNA转录本都能在宿主植物中引发感染，但子代病毒只包含一个外壳蛋白基因，没有额外的或缺失的核苷酸。基因组中两个功能性外壳蛋白基因顺序不同的突变体的子代保留了由差异核苷酸3'和5'处的重复核苷酸数量预测的外壳蛋白基因序列。相比之下，具有野生型和无功能外壳蛋白基因的病毒杂种产生的子代只拥有野生型外壳蛋白基因，即使预测的子代是游离RNA病毒。这表明选择强烈影响了哪些子代在最终群体中占主导地位。
