Arking R, Buck S, Berrios A, Dwyer S, Baker G T
Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202.
Dev Genet. 1991;12(5):362-70. doi: 10.1002/dvg.1020120505.
A long-lived (L) strain of Drosophila melanogaster, derived from a normal-lived (R) strain by artificial selection, has a significantly different adult longevity. Previous work has shown that 1) the two strains age in the same manner, 2) the major genes responsible for much of the L strain's extended longevity are located on the 3rd chromosome, and 3) the extended longevity phenotype is significantly modulated by the larval environment. In this report, we investigate the resistance of the L and R strains to the lethal effects of dietary paraquat. We show that, within the limitations of our described chromosomal and environmental manipulations, the extended longevity phenotype always accompanies the phenotype of elevated paraquat resistance. In addition, reversed selection applied to the L strain results in the simultaneous decrease of both life span and paraquat resistance. Thus, the presence or absence of the latter phenotype may be used as a bioassay for the presence or absence of the extended longevity phenotype, without any necessary implication of causality. Use of this bioassay should greatly speed up the genetic analysis of this system by allowing us to identify long-lived animals at a young age. Finally, we show that the age-related loss of elevated paraquat resistance in both strains precedes all the other age-related functional decrements which we have previously noted in this system.
一种通过人工选择从正常寿命（R）品系衍生而来的黑腹果蝇长寿（L）品系，其成虫寿命显著不同。先前的研究表明：1）这两个品系的衰老方式相同；2）负责L品系大部分延长寿命的主要基因位于第3号染色体上；3）延长寿命的表型受到幼虫环境的显著调节。在本报告中，我们研究了L品系和R品系对饮食中百草枯致死效应的抗性。我们发现，在所描述的染色体和环境操作的限制范围内，延长寿命的表型总是伴随着百草枯抗性升高的表型。此外，对L品系进行反向选择会导致寿命和百草枯抗性同时降低。因此，后一种表型的存在与否可作为延长寿命表型存在与否的生物测定方法，而无需任何因果关系的暗示。使用这种生物测定方法应能通过使我们在年轻时识别长寿动物，极大地加快该系统的遗传分析。最后，我们表明，两个品系中与年龄相关的百草枯抗性升高的丧失先于我们先前在该系统中注意到的所有其他与年龄相关的功能衰退。
