Shearn A, Rice T, Garen A, Gehring W
Proc Natl Acad Sci U S A. 1971 Oct;68(10):2594-8. doi: 10.1073/pnas.68.10.2594.
Late lethal mutants of Drosophila melanogaster, dying after the larval stage of development, were isolated. The homozygous mutant larvae were examined for abnormal imaginal disc morphology, and the discs were injected into normal larval hosts to test their capacities to differentiate into adult structures. In about half of the mutants analyzed, disc abnormalities were found. Included among the abnormalities were missing discs, small discs incapable of differentiating, morphologically normal discs with limited capacities for differentiation, and discs with homeotic transformations. In some mutants all discs were affected, and in others only certain discs. The most extreme abnormal phenotype is a class of "discless" mutants. The viability of these mutant larvae indicates that the discs are essential only for the development of an adult and not of a larva. The late lethals are therefore a major source of mutants for studying the genetic control of disc formation.
分离出了黑腹果蝇的晚期致死突变体，这些突变体在发育的幼虫阶段之后死亡。对纯合突变体幼虫进行检查，观察其成虫盘形态是否异常，并将这些成虫盘注射到正常幼虫宿主体内，以测试它们分化为成虫结构的能力。在大约一半被分析的突变体中，发现了成虫盘异常。异常情况包括缺失的成虫盘、无法分化的小成虫盘、形态正常但分化能力有限的成虫盘以及发生同源异型转化的成虫盘。在一些突变体中，所有成虫盘都受到影响，而在另一些突变体中，只有某些成虫盘受到影响。最极端的异常表型是一类“无成虫盘”突变体。这些突变体幼虫的活力表明，成虫盘仅对成虫的发育至关重要，而对幼虫的发育并非如此。因此，晚期致死突变体是研究成虫盘形成的遗传控制的主要突变体来源。
