Abstract

Beyond their classical role in preserving germline genome integrity via transposon silencing, piRNAs are increasingly recognized as pivotal regulators in somatic tissues. In these contexts, piRNAs orchestrate essential processes such as gut growth, gene expression regulation, metabolism, and the maintenance of intestinal homeostasis. Based on deep sequencing and bioinformatics, piR-ame-1128833 was previously detected to be significantly up-regulated. Here, we characterized the regulatory function of piR-ame-1128833 during the larval development of the western honeybee ( Apis mellifera ) worker. Integrative analysis of expression profiles and target predictions identified a significant negative correlation between piR-ame-1128833 and its predicted key target gene, AmYAP1 . Dual-luciferase reporter assays confirmed their direct interaction. Additionally, overexpression (knockdown) of piR-ame-1128833 resulted in marked down-regulation (up-regulation) AmYAP1 in larval guts. Functional experiments demonstrated that piR-ame-1128833 significantly impacted the expression of key developmental genes ultraspiracle protein ( USP ), Ecdysone receptor ( EcR ), and Wnt-1 as well as metabolic markers alpha glucosidase 2 ( AGLU2 ), ADP/ATP translocase ( Ant ), and vitellogenin ( Vg ), consequently impacting the larval viserosomatic index. Moreover, RNAi-mediated knockdown of AmYAP1 similarly led to not only dynamic change of the expression of aforementioned genes associated with gut development and metabolism but also a substantial reduction in the viserosomatic index. Collectively, these data suggest that piR-ame-1128833/AmYAP1 axis acts as a molecular switch that orchestrates the expression of downstream developmental and metabolic genes, ultimately influencing physiological parameters such as the viserosomatic index. Findings from this current work illustrate the m