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Shi JF, Cheng MH, Zhou W, Zeng MZ, Chen Y, Yang JX, Wu H, Ye QH, Tang H, Zhang Q, Fu KY, Guo WC. Crucial roles of specialized chitinases in elytral and hindwing cuticles construction in Leptinotarsa decemlineata. PEST MANAGEMENT SCIENCE 2024; 80:4437-4449. [PMID: 38656531 DOI: 10.1002/ps.8141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 03/25/2024] [Accepted: 04/24/2024] [Indexed: 04/26/2024]
Abstract
BACKGROUND The Colorado potato beetle (CPB), Leptinotarsa decemlineata, is a major potato (Solanum tuberosum) pest, infesting over 16 million km2 and causing substantial economic losses. The insect cuticle forms an apical extracellular matrix (ECM) envelope covering exposed organs to direct morphogenesis and confer structural protection. While select chitinase (Cht) genes have proven essential for larval development, their potential activities directing ECM remodeling underlying adult wing maturation remain undefined. RESULTS We investigated the expression patterns and performed an oral RNA interference (RNAi) screen targeting 19 LdChts in late-instar L. decemlineata larvae. Subsequently, we assessed their effects on adult eclosion and wing characteristics. Knockdown of LdCht5, LdCht7, LdCht10, LdIDGF2, and LdIDGF4, as well as others from Group IV (LdCht15, LdCht12, LdCht17, and LdCht13) and Groups VII-X (LdCht2, LdCht11, LdCht1, and LdCht3), resulting in shrunken, misshapen elytra with reduced areal density, as well as transverse wrinkling and impaired wing-tip folding in hindwings. Scanning electron micrographs revealed eroded elytral ridges alongside thinned, ruptured hindwing veins, indicative of mechanical fragility post-LdCht suppression. Spectroscopic analysis uncovered biomolecular alterations underlying the elytral anomalies, including decreases in peaks representing chitin, proteins, and lipids. This loss of essential ECM components provides evidence for the fragility, wrinkling, and shrinkage observed in the RNAi groups. CONCLUSION Our findings elucidate the crucial role of chitinases in the turnover of chitinous cuticles on beetle wings, offering insights into RNAi-based control strategies against this invasive pest. © 2024 Society of Chemical Industry.
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Affiliation(s)
- Ji-Feng Shi
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Chongqing, China
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Man-Hong Cheng
- Chongqing College of Humanities, Science and Technology, Chongqing, China
| | - Wei Zhou
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Chongqing, China
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Mu-Zi Zeng
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Yu Chen
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Jia-Xin Yang
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Hao Wu
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Qiu-Hong Ye
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Hong Tang
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Qing Zhang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
- Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Chongqing, China
- College of Sericulture, Textile, and Biomass Sciences, Southwest University, Chongqing, China
| | - Kai-Yun Fu
- Ministry of Agriculture/Xinjiang Key Laboratory of Agricultural Biosafety, Institute of Plant Protection Xinjiang Academy of Agricultural Sciences/Key Laboratory of Integrated Pest Management on Crops in Northwestern Oasis, Urumqi, China
| | - Wen-Chao Guo
- Ministry of Agriculture/Xinjiang Key Laboratory of Agricultural Biosafety, Institute of Plant Protection Xinjiang Academy of Agricultural Sciences/Key Laboratory of Integrated Pest Management on Crops in Northwestern Oasis, Urumqi, China
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de Andrade Soares HM, Rocha IC, Paprocki H, Fernandes GW. Mining tailings alter insects: revealing fluctuating asymmetry in the caddisfly Smicridea coronata. ENVIRONMENTAL MONITORING AND ASSESSMENT 2024; 196:531. [PMID: 38724710 DOI: 10.1007/s10661-024-12715-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Accepted: 05/06/2024] [Indexed: 06/21/2024]
Abstract
The Samarco/Vale/BHP mine tailing dam breach that took place in Minas Gerais, southeastern Brazil, in 2015, deposited high concentrations of metals and metalloids in the Rio Doce basin, severely impacting freshwater and riverine forest ecosystems. To assess developmental instability of caddisflies in response to the environmental impacts of the dam breach, we investigated the fluctuating asymmetry (FA) in the species Smicridea (Rhyacophylax) coronata (Trichoptera: Hydropsychidae). FA was assessed at individual and populational scales using geometric morphometric methods in the cephalic capsule and mandibles of larvae and also on the forewings of adults, both collected under the impacted condition, and under the least disturbed condition. The levels of FA increased in response to stressors on the forewings at the populational scale, and on the mandibles, at individual scale. These morphological variations in the larval and adult stages may lead to detrimental effects and result in high mortality rates as well as lower adult fitness. Trichoptera forewings are revealed as suitable traits for assessing FA, holding potential for applications in biomonitoring programs. Directional asymmetry levels were higher than FA levels for all traits, and this correlation could be explained by a transition from fluctuating to directional asymmetry in the presence of heightened disturbance. Our results validate the relationship between the impacts from the dam breach and increased developmental instability in this species with likely cascade effects on the insect community.
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Affiliation(s)
- Helena Maura de Andrade Soares
- Programa de Pós-Graduação Em Ecologia, Conservação E Manejo da Vida Silvestre, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
- Laboratório de Ecologia Evolutiva & Biodiversidade, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
| | | | - Henrique Paprocki
- Museu de Ciências Naturais, Pontifícia Universidade Católica de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Geraldo Wilson Fernandes
- Laboratório de Ecologia Evolutiva & Biodiversidade, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
- Knowledge Center for Biodiversity, Belo Horizonte, MG, Brazil
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Salcedo MK, Jung S, Combes SA. Autonomous Expansion of Grasshopper Wings Reveals External Forces Contribute to Final Adult Wing Shape. Integr Comp Biol 2023; 63:1111-1126. [PMID: 37715350 DOI: 10.1093/icb/icad121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 08/04/2023] [Accepted: 08/16/2023] [Indexed: 09/17/2023] Open
Abstract
Ecdysis, transformation from juvenile to adult form in insects, is time-consuming and leaves insects vulnerable to predation. For winged insects, the process of wing expansion during ecdysis, unfurling and expanding the wings, is a critical bottleneck in achieving sexual maturity. Internal and external forces play a role in wing expansion. Vigorous abdominal pumping during wing expansion allows insects to pressurize and inflate their wings, filling them with hemolymph. In addition, many insects adopt expansion-specific postures and, if inhibited, do not expand their wings normally, suggesting that external forces such as gravity may play a role. However, two previous studies over 40 years ago, reported that the forewings of swarming locusts can expand autonomously when removed from the emerging insect and laid flat on a saline solution. Termed "autoexpansion," we replicated previous experiments of autoexpansion on flat liquid media, documenting changes in both wing length and area over time while also focusing on the role of gravity in autoexpansion. Using the North American bird grasshopper Schistocerca americana, we tested four autoexpansion treatments of varying surface tension and hydrophobicity (gravity, deionized water, buffer, and mineral oil) while simultaneously observing and measuring intact, normal wing expansion. Finally, we constructed a simple model of a viscoelastic expanding wing subjected to gravity, to determine whether it could capture aspects of wing expansion. Our data confirmed that wing autoexpansion does occur in S. americana, but autoexpanding wings, especially hindwings, failed to increase to the same final length and area as intact wings. We found that gravity plays an important role in wing expansion, early in the expansion process. Combined with the significant mass increase we documented in intact wings, it suggests that hydraulic pumping of hemolymph into the wings plays an important role in increasing the area of expanding wings, especially in driving expansion of the large, pleated hindwings. Autoexpansion in a non-swarming orthopteran suggests that local cues driving wing autoexpansion may serve a broader purpose, reducing total expansion time and costs by shifting some processes from central to local control. Documenting wing autoexpansion in a widely studied model organism and demonstrating a mathematical model provides a tractable new system for exploring higher level questions about the mechanisms of wing expansion and the implications of autoexpansion, as well as potential bioinspiration for future technologies applicable to micro-air vehicles, space exploration, or medical and prosthetic devices.
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Affiliation(s)
- Mary K Salcedo
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Sunghwan Jung
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Stacey A Combes
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, 95616, USA
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