Evidence for an Inducible Repair-Recombination System in the Female Germ Line of Drosophila melanogaster. III. Correlation Between Reactivity Levels, Crossover Frequency and Repair Efficiency

Abstract

We previously reported evidence that the so-called reactivity level, a peculiar cellular state of oocytes that regulates the frequency of transposition of I factor, a LINE element-like retrotransposon, might be one manifestation of a DNA repair system. In this article, we report data showing that the reactivity level is correlated with the frequency of crossing over, at least on the X chromosome and on the pericentromeric region of the third chromosome. Moreover, a check for X-chromosome losses and recessive lethals produced after gamma irradiation in flies with different reactivity levels, but common genetic backgrounds, brings more precise evidence for the relationship between reactivity levels and DNA repair. Those results support the existence of a repair-recombination system whose efficiency is modulated by endogenous and environmental factors. The implications of this biological system in connecting genomic variability and environment may shed new lights on adaptative mechanisms. We propose to call it VAMOS for variability modulation system.

Parental age effect on the longevity and healthspan in Drosophila melanogaster and Caenorhabditis elegans

“…We investigated the impact of parental age on the lifespan of D. melanogaster using two strains here named A and B , which were examined as part of a larger study (see materials and methods, [ 33 , 34 ]) with the experimental setup shown in Figure 1B . The average parental age was 4 ± 2 days for the SG isolines and 40 ± 2 days and 20 ± 2 days, respectively for A and B , for the LG isolines ( Figure 1 ).…”