Silencing Miniature Gene Disrupts Elytral and Hindwing Structures in Leptinotarsa decemlineata

TL;DR

Silencing the LdMi gene in Colorado potato beetles causes wing deformities and weakens their protective cuticle, potentially offering new pest control strategies.

Contribution

This study reveals the functional role of the LdMi gene in wing and cuticle development in Leptinotarsa decemlineata using RNA interference.

Findings

Knockdown of LdMi caused severe elytral and hindwing deformities in Leptinotarsa decemlineata.

LdMi knockdown reduced protein–chitin crosslinking and hydrogen bonding in the cuticle.

LdMi is highly expressed in hindwings, elytra, and pupal stages of the beetle.

Abstract

The Colorado potato beetle (Leptinotarsa decemlineata) is a destructive pest that causes significant damage to potato crops. The beetle’s wings are crucial for its flight, and survival, and protection against environmental stressors, such as pesticides, which also make controlling this pest difficult. The Miniature (Mi) gene plays an essential role in the development of the wings and their protective outer covering (cuticle) in Drosophila melanogaster. In this study, we investigated the function of the LdMi gene in L. decemlineata using RNA interference to suppress its expression. Our results demonstrate that knockdown of the LdMi gene caused severe deformities in the elytra and hindwings of the beetle, with significant changes in the chemical composition of the wings, weakening their structural integrity. This study highlights the critical role of the LdMi gene in wing development and provides valuable insights into advancing pest control strategies.

The Colorado potato beetle (Leptinotarsa decemlineata, CPB) is a major pest in potato crops, notorious for its rapid dispersal and insecticide resistance, which are enabled by its robust elytra and flight-capable hindwings. The Miniature (Mi) gene, encoding a protein with a zona pellucida (ZP) domain, is involved in wing development and cuticle integrity, yet its functional role in beetles remains underexplored. In this study, we cloned and characterized the LdMi gene in the CPB and investigated its function using RNA interference (RNAi), morphological analyses, and spectroscopy. LdMi encodes a 146.35 kDa transmembrane protein with a conserved ZP domain, clusters with coleopteran homologs, and exhibits relative conservation across insect species. Expression profiling showed high LdMi transcript levels in the hindwings, the elytra, and the pupal stages. RNAi knockdown in fourth-instar larvae resulted in severe eclosion defects, including malformed wings and reduced adult weight. Scanning electron microscopy (SEM) revealed disrupted elytral patterns and deformed hindwing veins in knockdown individuals. Spectroscopic analyses using Fourier-transform infrared (FTIR) and Raman spectroscopy indicated a reduction in protein–chitin crosslinking and diminished hydrogen bonding, suggesting compromised cuticular integrity. These results highlight the essential role of LdMi in cuticle formation and the surface morphology of the elytra and hindwings, offering new insights into ZP domain proteins in insects.

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