Lönnig W E, Saedler H
Max-Planck-Institut für Züchtungsforschung, Köln, Germany.
Mol Gen Genet. 1994 Dec 1;245(5):636-43. doi: 10.1007/BF00282227.
Plants of Antirrhinum majus carrying the semidominant Macho alleles of the plena gene display carpelloid sepals and staminoid petals, but the two inner flower whorls of stamens and carpels are normal and produce fertile gametes. In the recessive plena mutant, in contrast, the two outer whorls are normal whereas the stamens are largely or entirely petaloid and the carpels sepaloid, thus producing weakly male-fertile or fully sterile lines. Two new plena and two new Macho alleles have been induced in transposon tagging experiments. Genetic and molecular analysis revealed that the two contrasting mutant phenotypes are caused by mutations in one and the same gene: Several wild-type plants appeared among 27,000 F1 plants of a cross between Macho female plants and wild-type males bearing the active transposons Tam1 and Tam3. One of these plants segregated plena mutants, three showed reversions to wild-type and another two segregated Macho plants, possibly representing somatic reversions. Additional evidence was provided by an allelism test of Macho x plena. Molecular analysis has independently corroborated the genetical results. Moreover, the double mutant Macho/deficiens shows only carpels and plena/deficiens only sepals, which is in accord with combinatorial models for homeotic flower formation presented recently.
携带重瓣基因半显性Macho等位基因的金鱼草植株表现出心皮状萼片和雄蕊状花瓣，但雄蕊和心皮这两个内轮花器官正常并能产生可育配子。相比之下，在隐性重瓣突变体中，外两轮花器官正常，而雄蕊大多或完全呈花瓣状，心皮呈萼片状，从而产生雄性育性弱或完全不育的株系。在转座子标签实验中诱导出了两个新的重瓣等位基因和两个新的Macho等位基因。遗传和分子分析表明，这两种截然不同的突变表型是由同一个基因的突变引起的：在携带活性转座子Tam1和Tam3的Macho雌株与野生型雄株杂交的27000株F1植株中出现了几株野生型植株。其中一株分离出重瓣突变体，三株表现出回复到野生型，另外两株分离出Macho植株，可能代表体细胞回复突变。Macho与重瓣的等位性测验提供了额外的证据。分子分析独立证实了遗传结果。此外，双突变体Macho/deficiens只表现出心皮，重瓣/deficiens只表现出萼片，这与最近提出的花同源异型形成的组合模型一致。
