Long-term selection for faster development and early reproduction leads to up-regulation of genes involved in redox homeostasis

Heightened immune surveillance in Drosophila melanogaster populations selected for faster development and extended longevity

“…Indeed, it is likely that increased ecdysone levels are responsible for the heightened immune function in our selected populations. The enhanced immune activity through melanization, phagocytosis, redox homeostasis and upregulation of key AMPs responsible for defense against pathogenic microbes is likely to have contributed to comparable larval survival in the selected and control populations ( Sharma et al., 2020 ; Shrivastava et al., 2022 ) as against reduced larval survival in the populations selected for faster pre-adult development and early reproduction ( Prasad et al., 2000 , 2001 ). In our opinion, this is the first extensive in vivo study that shows selection for faster pre-adult development and extended adult longevity in Drosophila melanogaster leads to enhanced immune activity in the larval stage, leading to comparable larval survival.…”

“…The S populations had been through a total of 180 generations of selection when this study was initiated. The C and S populations have been referred to as JB (Joshi Baseline) and FLJ ( F aster developing L ate reproducing J B derived) ( Rajamani et al., 2006 ; Shrivastava et al., 2022 ), or Genotypically Large and Genotypically Small ( Handa et al., 2014 ); in our earlier publications. Further, our selected populations share their ancestral populations (Control/JB/Genotypically Large) with the F aster developing E arly reproducing J B derived (FEJ) populations of Prasad et al.…”

“…The C and S populations were passed through one generation of common rearing conditions in order to eliminate all non-genetic effects ( Prasad et al., 2001 ; Sharma et al., 2020 ; Shrivastava et al., 2022 ). The egg collection from C and S populations was staggered by the developmental time difference such that the chronological age of the parents of assay flies as well as that of assay flies themselves were comparable ( Sharma et al., 2020 ; Chauhan et al., 2020 ; Shrivastava et al., 2022 ), these flies were termed as standardized flies ( Figure 1 c). All the experiments were done using the progeny of standardized flies.…”

“…The first three plates were of SM and the last plate was of non-nutritive agar. Eggs laid on the agar plate were used in all the experiments, while those laid on the 3 SM plates were discarded ( Sharma et al., 2020 ; Chauhan et al., 2020 ; Shrivastava et al., 2022 ). Egg collection from C and S populations were staggered by their developmental time difference so as to obtain larvae of similar physiological state at a given sampling time ( Figure 1 c).…”

“…Populations of P. interpunctella selected for shorter development time showed increased resistance to PiGV, while those selected for longer development time showed decreased resistance to PiGV, thus showing the non-symmetrical nature of trade-offs ( Bartlett et al., 2020 ). Two recent studies, reported that D. melanogaster populations selected for faster pre-adult development and extended reproductive lifespan showed both, larval survival ( Sharma et al., 2020 ; Shrivastava et al., 2022 ) and adult longevity ( Sharma and Shakarad, 2021 ) to be comparable with control populations despite being under selection for extended reproductive lifespan. However, life-time fecundity was significantly lower ( Sharma and Shakarad, 2021 ).…”