Neglecting larval rearing conditions in Drosophila melanogaster can negatively impact research on ageing

A Link between Atmospheric Pressure and Fertility of Drosophila Laboratory Strains

Simple Summary

The researchers usually keep insects under study under thoroughly controlled conditions. However, sometimes they encounter a situation where the data they obtained under such conditions demonstrate an obvious side effect of some unaccounted factor. Here we provide evidence that changes in atmospheric pressure could be responsible for some such cases.

Abstract

Standardization of conditions under which insects are kept is of great importance when studying their physiology and researchers do their best to maintain it. Nevertheless, sometimes an obvious side effect of some unaccounted factor affecting insects’ reproduction can be revealed even under thoroughly controlled laboratory conditions. We faced such a phenomenon when studying the fertility level in two wild type Drosophila melanogaster strains. For fertility analysis, 50 newly emerged females and 50 males of each strain under study were transferred to fresh medium daily within 10 days. We found out that fertility of both strains was stable on days 2–10 after the oviposition onset in one experiment, while in another one it was significantly decreased during days 5–10. When compared to publicly available meteorological data, these changes in the fertility level demonstrated a strong association with one weather factor: barometric pressure. Thus, we conclude that changes in atmospheric pressure can be considered a factor affecting insects reproduction and discuss a possible mechanism of their influence on fertility.

Is lifespan linked with developmental viability in Drosophila melanogaster?

Long-lived lines of flies have been selected by reproduction at older ages and correlated responses observed, and particularly whether development of flies was modified. Using these selected lines or flies subjected to larval crowding of food restriction during development, two studies have computed, among lines, a correlation between viability of eggs and larvae and mean lifespan of adults: mean lifespan was longer when the viability was lower, showing a selection of fittest flies. The present study correlates viability and mean lifespan observed during three decades in a single wild-type strain. Contrary to the previous studies, a slight but not significant positive correlation is observed, showing that lifespan can hardly increase when viability increases. Therefore, it is not clear whether development and lifespan are linked, as hypothesised by some authors.