Adaptation of Drosophila melanogaster to unfavorable growth medium affects lifespan and age-related fecundity

Abstract

Experimental adaptation of Drosophila melanogaster to nutrient-deficient starch-based (S) medium resulted in lifespan shortening, increased early-life fecundity, accelerated reproductive aging, and sexually dimorphic survival curves. The direction of all these evolutionary changes coincide with the direction of phenotypic plasticity observed in non-adapted flies cultured on S medium. High adult mortality rate caused by unfavorable growth medium apparently was the main factor of selection during the evolutionary experiment. The results are partially compatible with Williams' hypothesis, which states that increased mortality rate should result in relaxed selection against mutations that decrease fitness late in life, and thus promote the evolution of shorter lifespan and earlier reproduction. However, our results do not confirm Williams' prediction that the sex with higher mortality rate should undergo more rapid aging: lifespan shortening by S medium is more pronounced in naïve males than females, but it was female lifespan that decreased more in the course of adaptation. These data, as well as the results of testing of F hybrids between adapted and control lineages, are compatible with the idea that the genetic basis of longevity is different in the two sexes, and that evolutionary response to increased mortality rate depends on the degree to which the mortality is selective. Selective mortality can result in the development of longer (rather than shorter) lifespan in the course of evolution. The results also imply that antagonistic pleiotropy of alleles, which increase early-life fecundity at the cost of accelerated aging, played an important role in the evolutionary changes of females in the experimental lineage, while accumulation of deleterious mutations with late-life effects due to drift was more important in the evolution of male traits.

Does adaptation to different diets result in assortative mating? Ambiguous results from experiments on Drosophila

“…Lines reared on these stressful media have been demonstrated to show signs of successful adaptation to their respective environments (Dmitrieva et al ., ; Markov et al ., ). Moreover, line Starch1 evolved higher early fecundity, accelerated reproductive ageing, and shorter lifespan compared to Rich1 line (Yakovleva et al ., ). This is an expected evolutionary response to high adult mortality (Williams, ) caused in this experiment by living on the unfavourable starch‐based medium.…”

Cytoprotective, antimutagenic/antirecombinogenic and antibacterial properties of Lallemantia iberica extracts

“…Two D. melanogaster strains, called flr3 (flare‐3, flr 3 / In ( 3LR ) TM3 , Bd s ) and mwh (multiple wing hairs strain with the genetic constitution y ; mwh j ) were used in this study 14 . The strains were kept at 22 °C in glass bottles with standard growth media 31,32 . Growth medium was prepared by dissolving 43 g sugar in 500 mL distilled water at 100 °C on a magnetic stirrer.…”

Drosophila as a Model Organism to Study Basic Mechanisms of Longevity

“…Flies are characterized by high fecundity (about 200 offspring per female), which allows for analysis of any feature of interest over hundreds of individuals to avoid statistical anomalies. Drosophila practically possesses one significant advantage over mammalian models in the aging field, that is short life cycle and lifespan of ~60–70 days for laboratory isogenic wild-type strains and ~120–130 days for non-isogenic flies from natural populations [ 12 ]. Drosophila overwinters in nature in the adult stage in vegetable warehouses, etc., wherever the temperature reaches 16 °C.…”