Jumping genes and AFLP maps: transforming lepidopteran color pattern genetics

Abstract

Summary The color patterns on the wings of lepidopterans are among the most striking patterns in nature and have inspired diverse biological hypotheses such as the ecological role of aposomatic coloration, the evolution of mimicry, the role of human activities in industrial melanism, and the developmental basis of phenotypic plasticity. Yet, the developmental mechanisms underlying color pattern development are not well understood for three reasons. First, few mutations that alter color patterns have been characterized at the molecular level, so there is little mechanistic understanding of how mutant phenotypes are produced. Second, although gene expression patterns resembling adult color patterns are suggestive, there are few data available showing that gene products have a functional role in color pattern formation. Finally, because with few exceptions (notably Bombyx), genetic maps for most species of Lepidoptera are rudimentary or nonexistent, it is very difficult to characterize spontaneous mutants or to determine whether mutations with similar phenotypes are because of lesions in the same gene or different genes. Discussed here are two strategies for overcoming these difficulties: germ‐line transformation of lepidopteran species using transposon vectors and amplified frequency length polymorphism‐based genetic mapping using variation between divergent strains within a species or between closely related and interfertile species. These advances, taken together, will create new opportunities for the characterization of existing genetic variants, the creation of new sequence‐tagged mutants, and the testing of proposed functional genetic relationships between gene products, and will greatly facilitate our understanding of the evolution and development of lepidopteran color patterns.

Small Interfering RNA Pathway Modulates Initial Viral Infection in Midgut Epithelium of Insect after Ingestion of Virus

“…The higher efficiency of DCR2 than AGO2 inhibition of viral replication in SBPH or WBPH cells coincides with the major role of DCR2 in mediating the restriction of arbovirus replication in insect vectors (44). This phenomenon may be explained by the involvement of DCR2 and AGO2 in different steps during the siRNA antiviral response (12,(44)(45)(46)(47).…”

A rearrangement of the Z chromosome topology influences the sex-linked gene display in the European corn borer, Ostrinia nubilalis

“…Genes encoded on the Z chromosome of Lepidoptera are involved in the differentiation of ecotypes and speciation (Hagen and Scriber 1989;Sperling 1994;Jiggins et al 2001a, b), but the isolation of genes or chromosome regions regulating these traits is hindered in part by the absence of a dense genetic linkage map for each species (Marcus 2005). To partially address these shortfalls, we created a genetic linkage map for the O. nubilalis Z chromosome that was based on gene orthologs that can be identified across multiple species of Lepidoptera.…”

Molecular Population Structure ofJunoniaButterflies from French Guiana, Guadeloupe, and Martinique

“…Junonia species have been widely used to study the evolution and development of butterfly wing colour patterns [2][3][4][5][6][7][8][9]. Experimental tools to manipulate gene expression developed in Junonia are broadly applicable across the Lepidoptera [10][11][12][13][14].…”

“…Buckeye butterflies, genus Junonia (Nymphalidae), are an important model system for experimental research in the Lepidoptera [1,2]. Junonia species have been widely used to study the evolution and development of butterfly wing colour patterns [2][3][4][5][6][7][8][9].…”