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

Correlated responses in basal immune function in response to selection for fast development in Drosophila melanogaster

“…The upregulation of these genes suggests activation of Imd pathway and it has been reported that the flies that develop with Imd activation in larvae tend to have short lifespan (Yamashita et al, 2021) that might be an outcome of selection pressure for short effective lifespan in FEJs (Mital et al, 2022). The comparison of transcript levels of seven AMPs among FLJs and JBs although differed in absolute values, yielded identical results as reported in earlier study (Shrivastava, Chauhan, & Shakarad, 2022). However, Dro was upregulated in JBs in comparison with both FEJs and FLJs.…”

“…The increased innate immunity in FEJ populations as correlated response to increased developmental speed, could be due to higher microbial load in the larval culture vials (Dey et al, 2016) facilitated by reduced larval feeding rate (Prasad et al, 2001) and increased ecdysone levels (Chauhan et al, 2020). However, our second hypothesis was borne out in that, the FLJs have evolved both, the cellular arm (Shrivastava, Chauhan, & Shakarad, 2022) and humoral arm (as indicated by significantly higher Drs levels) of innate immunity (this study). This study also shows how insulin signalling, ecdysone and immune system might be functioning together to maintain physiological homeostasis and thus helping the organisms under selection for rapid development to emerge as fully functional adults.…”

“…The egg to adult development time of FLJs was ~7.5 days and eggs for obtaining flies for the following generation were collected when the adult age was ~35 days. Maintenance protocol is described in detail by Sharma et al (2020) and Shrivastava, Chauhan, and Shakarad (2022). In all, we have used a total of nine populations, three from each kind.…”

“…The first three plates contained banana–jaggery media, while the fourth plate was of non‐nutritive agar. In all the experiments, eggs laid on the non‐nutritive agar plate were used, while those laid on the first three banana–jaggery media plates were discarded (Sharma et al, 2020; Shrivastava, Chauhan, & Shakarad, 2022). The collection of eggs from the JB, FEJ and FLJ populations was staggered according to their developmental time differences to obtain late L3 larvae from all the populations at the same sampling time.…”

“…All statistical analyses were performed on Real Statistics Add‐Ins in MS Excel. Plasmatocyte and crystal cell data of JB and FLJ was taken from Shrivastava, Chauhan, and Shakarad (2022).…”