Insulin receptors and wing dimorphism in rice planthoppers

Abstract

Wing polymorphism contributes significantly to the success of a wide variety of insects. However, its underlying molecular mechanism is less well understood. The migratory planthopper (BPH), Nilaparvata lugens , is one of the most extensively studied insects for wing polymorphism, due to its natural features of short- and long-winged morphs. Using the BPH as an example, we first surveyed the environmental cues that possibly influence wing developmental plasticity. Second, we explained the molecular basis by which two insulin receptors (InR1 and InR2) act as switches to determine alternative wing morphs in the BPH. This finding provides an additional layer of regulatory mechanism underlying wing polymorphism in insects in addition to juvenile hormones. Further, based on a discrete domain structure between InR1 and InR2 across insect species, we discussed the potential roles by which they might contribute to insect polymorphism. Last, we concluded with future directions of disentangling the insulin signalling pathway in the BPH, which serves as an ideal model for studying wing developmental plasticity in insects. This article is part of the themed issue ‘Evo-devo in the genomics era, and the origins of morphological diversity’.

The genetic and molecular architecture of phenotypic diversity in sticklebacks

“…The development of new genome-editing tools like TALENs and CRISPR/Cas9 for use in sticklebacks [22] will greatly facilitate this research, enabling us to discern whether there are general patterns in the genetic and molecular architecture of phenotypic evolution, at least in sticklebacks. It will also be important to compare results in sticklebacks to those in other systems, like those highlighted in this special issue [77][78][79][80][81], to determine whether the genetic and molecular basis of phenotypic evolution is contingent on the study system or whether general evolutionary patterns will emerge. This review has focused on recent efforts to identify the links between phenotype and genotype in order to understand phenotypic diversity.…”

The MTase15 regulates reproduction in the wing‐dimorphic planthopper, Nilaparvata lugens (Hemiptera: Delphacidae)

“…Wing dimorphism in BPH is one of the intensively studied examples of wing polymorphism in insects (Xu and Zhang, ). LW BPHs are flight capable because of well‐developed wings and flight apparatus, allowing them to explore new habitats across wide geographical areas.…”

“…It feeds exclusively on rice plants and can cause their complete wilting and drying (Sogawa, ; Backus et al , ), leading to huge losses in rice yields. Wing dimorphism – that is, the ability to develop into either long‐winged (LW) or short‐winged (SW) adults – and high fecundity contribute significantly to the ecological success of BPHs in natural and agricultural habitats (Xu and Zhang, ). Recently, we found that development of LW and SW BPHs was regulated by an insulin/insulin‐like growth factor signalling (IIS) pathway (Xu et al , ; Zhang et al , ).…”

Perspectives on the history of evo-devo and the contemporary research landscape in the genomics era

“…In this issue, Xu & Zhang [49] describe the striking developmental plasticity of brown planthoppers in which short-winged and long-winged hoppers develop depending on environmental factors, including temperature and population density. The basis of the alternative wing morphologies in these hoppers has been traced to the activity of two insulin receptors with opposite effects on wing bud growth.…”

“…The next section focuses on diversification and modifications of morphology as exemplified by tetrapod limbs by Saxena et al [54], flowers by Pam Soltis and co-workers [55], cranial shape in birds by Abzhanov and co-workers [45] and wing coloration patterns in butterflies by Jiggins et al [56]. The last section considers the relatively recent evolution of genetically determined morphological variation within a single species owing to either natural selection, using as examples, cavefish (article by Krishnan & Rohner [57]) and stickleback (article by Piechel & Marques [58]) or artificial selection, using dogs as an example (article by Elaine Ostrander and co-workers [59]) and ends with the article on developmental plasticity by Xu & Zhang [49].…”