Phase-related differences in egg production of the migratory locust regulated by differential oosorption through microRNA-34 targeting activinβ

Abstract

Outbreaks of locust plagues result from the long-term accumulation of high-density egg production. The migratory locust, Locusta migratoria, displays dramatic differences in the egg-laid number with dependence on population density, while solitarious locusts lay more eggs compared to gregarious ones. However, the regulatory mechanism for the egg-laid number difference is unclear. Herein, we confirm that oosorption plays a crucial role in the regulation of egg number through the comparison of physiological and molecular biological profiles in gregarious and solitarious locusts. We find that gregarious oocytes display a 15% higher oosorption ratio than solitarious ones. Activinβ (Actβ) is the most highly upregulated gene in the gregarious terminal oocyte (GTO) compared to solitarious terminal oocyte (STO). Meanwhile, Actβ increases sharply from the normal oocyte (N) to resorption body 1 (RB1) stage during oosorption. The knockdown of Actβ significantly reduces the oosorption ratio by 13% in gregarious locusts, resulting in an increase in the egg-laid number. Based on bioinformatic prediction and experimental verification, microRNA-34 with three isoforms can target Actβ. The microRNAs display higher expression levels in STO than those in GTO and contrasting expression patterns of Actβ from the N to RB1 transition. Overexpression of each miR-34 isoform leads to decreased Actβ levels and significantly reduces the oosorption ratio in gregarious locusts. In contrast, inhibition of the miR-34 isoforms results in increased Actβ levels and eventually elevates the oosorption ratio of solitarious locusts. Our study reports an undescribed mechanism of oosorption through miRNA targeting of a TGFβ ligand and provides new insights into the mechanism of density-dependent reproductive adaption in insects.

The accumulation of modular serine protease mediated by a novel circRNA sponging miRNA increases Aedes aegypti immunity to fungus

“…The fluorescence results indicated that miRNA-novel-53 and ModSP are both localized in the cytoplasm. These results are similar to those of previous studies showing that miRNA and its target gene both play roles in the cytoplasm [ 58 , 59 ]. Mature miRNA-novel-53 is transported into the cytoplasm to inhibit the translation of ModSP transcripts and downregulate its expression level.…”

Argonaute1 and Gawky Are Required for the Development and Reproduction of Melon fly, Zeugodacus cucurbitae

“…The high expression of Ago1 in the ovary and Gawky in the head implies that these genes play important roles in these tissues. Previous studies have shown that Ago1 is highly expressed in Drosophila oocytes, while in B. mori , it is mainly expressed in the ovary, testis, midgut, and head ( Wu et al, 2021 ; Yang et al, 2021 ; Zhao et al, 2021 ). These various expression patterns may be due to the specific functions of Ago1 genes in different insect species.…”

RNA sequencing identifies an ovary‐enriched microRNA, miR‐311‐3p, involved in ovarian development and fecundity by targeting EndophilinB1 in Bactrocera dorsalis

“…Additionally, we found that miR‐34 was upregulated during sexual maturation in the fat body of B. dorsalis , indicating that it was possibly involved in reproductive development. Interestingly, miR‐34 plays distinct roles in different insect species, including wing polyphenism, 57 larval growth and wing morphogenesis, 58 oosorption 59 etc. These studies suggest that miRNAs differ in their reproductive roles among different species.…”