Wilson T G, Fabian J
Dev Biol. 1986 Nov;118(1):190-201. doi: 10.1016/0012-1606(86)90087-4.
Methoprene, a chemical analog of juvenile hormone, is toxic when applied to late third-instar larvae of Drosophila melanogaster. Using an ethyl methane sulfonate mutagenesis screen, we have selected two noncomplementing mutants, one of which is nearly 100 times more resistant than wild-type to either methoprene or juvenile hormone III topically applied or incorporated into the diet. The mutation, named methoprene-tolerant (Met), also confers resistance to methoprene-induced pseudotumor formation in larvae as well as to juvenile hormone III- or methoprene-induced vitellogenic oocyte development in adult females. Met adults show little or no cross-resistance to four other insecticides. The mutation was mapped by recombination to a location 35.4 on the X-chromosome and uncovered by chromosomes deficient for the region 10C2-10D4. Complementation was observed between Met and a lethal allele of the RNA polymerase II locus, which is also found in this region. Since the Met mutation also confers resistance to methoprene-induced abnormalities in adult cuticle formation, the autonomy of Met expression could be evaluated in flies mosiac for this mutation. Autonomous expression of Met was found both in abdominal cuticle as well as in external male genitalia. The characteristics of Met are consistent with those expected of a mutant having altered juvenile hormone reception in target tissue.
烯虫酯是一种保幼激素的化学类似物，当应用于黑腹果蝇的三龄晚期幼虫时具有毒性。通过乙磺酸乙酯诱变筛选，我们挑选出了两个非互补突变体，其中一个对局部涂抹或添加到食物中的烯虫酯或保幼激素III的抗性比野生型高近100倍。这个名为耐烯虫酯（Met）的突变，还使幼虫对烯虫酯诱导的假瘤形成以及成年雌蝇对保幼激素III或烯虫酯诱导的卵黄生成卵母细胞发育产生抗性。Met成年个体对其他四种杀虫剂几乎没有或没有交叉抗性。通过重组将该突变定位到X染色体上35.4的位置，并且该区域10C2 - 10D4缺失的染色体可揭示该突变。在Met与RNA聚合酶II基因座的一个致死等位基因之间观察到互补现象，该致死等位基因也位于该区域。由于Met突变也使成年果蝇表皮形成对烯虫酯诱导的异常产生抗性，因此可以在该突变的镶嵌果蝇中评估Met表达的自主性。在腹部表皮以及雄性外生殖器中均发现了Met的自主表达。Met的特征与预期的在靶组织中改变了保幼激素受体的突变体的特征一致。
