biostudies-literatureLiu ZNational Science Foundation of China1342-1351https://www.ebi.ac.uk/biostudies/studies/S-EPMC7549633biostudies-literatureUnknown17(9)microRNAs (miRNA) are small non-coding RNAs that modulate the myriad biological activities by targeting genes, and many studies showed that miRNAs played a pivotal role in insect development. Here, we find that Bm-miRNA (miR-34) controls larval growth and wing morphology by targeting <i>BmE74</i> and <i>BmCPG4</i>. Overexpression of miR-34 in the whole body caused a smaller body size, partially displays deformed wings and venation defects in adults. Ablation of miR-34 by transgenic CRISPR/Cas9 technology resulted in a severe developmental delay during the larval stage. Moreover, we confirmed that miR-34 directly targeted <i>BmE74</i> and <i>BmCPG4</i> by using a dual luciferase reporter assay in HEK293T cells. Remarkably, loss-of-function of <i>BmCPG4</i> caused wing defects, which was simRNA biologymiR-34 regulates larval growth and wing morphogenesis by directly modulating ecdysone signalling and cuticle protein in <i>Bombyx mori</i>.PMC754963331530072Yang XLiu ZHuang YZhang XLing LLuo XYang DXu JfalsemiR-34 regulates larval growth and wing morphogenesis by directly modulating ecdysone signalling and cuticle protein in <i>Bombyx mori</i>.microRNAs (miRNA) are small non-coding RNAs that modulate the myriad biological activities by targeting genes, and many studies showed that miRNAs played a pivotal role in insect development. Here, we find that Bm-miRNA (miR-34) controls larval growth and wing morphology by targeting <i>BmE74</i> and <i>BmCPG4</i>. Overexpression of miR-34 in the whole body caused a smaller body size, partially displays deformed wings and venation defects in adults. Ablation of miR-34 by transgenic CRISPR/Cas9 technology resulted in a severe developmental delay during the larval stage. Moreover, we confirmed that miR-34 directly targeted <i>BmE74</i> and <i>BmCPG4</i> by using a dual luciferase reporter assay in HEK293T cells. Remarkably, loss-of-function of <i>BmCPG4</i> caused wing defects, which was sim2020-01-01T00:00:00Z2020 Sep2025-04-26T00:09:20.351Z2025-04-06T09:37:54.677ZS-EPMC75496333240114110.1080/15476286.2020.1767953