eIF3 subunit M regulates blood meal digestion in Rhodnius prolixus affecting ecdysis, reproduction, and survival

Abstract

In triatomines, blood‐feeding triggers many physiological processes including post embryonic development and reproduction. Different feeding habits, such as hematophagy, can shape gene functions to meet the challenges of each type of diet. The gut of blood‐sucking insects faces particular challenges after feeding due to the quantity and the quality of the food ingested. A comparison of transcriptomic and proteomic data indicates that post transcriptional regulation of gene expression is crucial in the triatomine gut. It was proposed that eukaryotic translation initiation factor 3 subunit m (eIF3m) and eIF3e define 2 different eIF3 complexes with a distinct affinity for the different mRNAs, thus selecting the set of mRNAs to be translated and constituting a post transcriptional mode of regulation of gene expression. Because the eIF3m is mainly expressed in the gut, we evaluated its relevance in Rhodnius prolixus physiology through RNA interference‐mediated gene silencing. The knockdown of eIF3m reduced the digestion rate, affecting the processes triggered by a blood meal. Its silencing inhibited molting and caused premature death in nymphs while impaired ovary development, oviposition and increased resistance to starvation in adult females. The survival of males after feeding (resistance to starvation) was not affected by eIF3m knockdown. The information regarding the eIF3m function in insects is scarce and the phenotypes observed in R. prolixus upon eIF3m silencing are different and more severe than those previously described in Drosophila melanogaster, indicating a pleiotropic role of this gene in triatomines.

Drosophila eIF3f1 mediates host immune defense by targeting dTak1

“…Regardless, it is not possible to formally exclude the possibility that the translation initiation function might be performed by eIF3f2. A series of recent studies have demonstrated that some of the fly eIF3 subunits, for instance eIF3d, eIF3m, and eIF3j, are involved in regulating tissue/organ development, stress response, and so on (Ameijeiras et al, 2023 ; Ramat et al, 2020 ; Song et al, 2022 ; Szostak et al, 2018 ). All these functions are fulfilled through a translational control-dependent manner.…”