Howells A J
Biochem Genet. 1979 Feb;17(1-2):149-58. doi: 10.1007/BF00484480.
Six new ems-induced scarlet mutants were selected. Four of these were partially pigmented, with xanthommatin levels ranging from 12% to 45% of normal. In one (st754ts), pigment production was temperature sensitive; the level of xanthommatin changed from less than 10% of normal at 29 C to more than 70% at 18 C. In all of the new mutants tested, the level of early pupal 3-hydroxykynurenine was as low as that in st1. Thus reduced larval accumulation of this metabolite also appears to be a characteristic feature of scarlet mutants. Temperature-pulse and temperature-shift experiments were carried out with st754ts to determine the temperature-sensitive period for the scarlet gene during development. The major sensitive period commenced prior to the onset of pigmentation and was over before adult emergence. Thus the initiation of xanthommatin synthesis is not brought about by the activation of the scarlet gene. In similar experiments carried out with a temperature-sensitive white mutant (Wbl), a similar temperature-sensitive period was obtained.
筛选出了六个新的经EMS诱导产生的猩红色突变体。其中四个突变体部分着色，黄蝶呤水平为正常水平的12%至45%。在其中一个突变体（st754ts）中，色素产生对温度敏感；黄蝶呤水平在29℃时低于正常水平的10%，而在18℃时则超过70%。在所有测试的新突变体中，早期蛹期3-羟基犬尿氨酸的水平与st1中的水平一样低。因此，这种代谢物在幼虫期积累减少似乎也是猩红色突变体的一个特征。对st754ts进行了温度脉冲和温度转换实验，以确定发育过程中猩红色基因的温度敏感期。主要敏感期在色素沉着开始之前开始，并在成虫羽化之前结束。因此，黄蝶呤合成的起始不是由猩红色基因的激活引起的。在用一个温度敏感的白色突变体（Wbl）进行的类似实验中，也获得了类似的温度敏感期。
