Collaborative Research: EDGE CMT: Mechanistic basis of cricket wing dimorphism: predicting phenotype from genotype in complex threshold traits

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

Many traits, including disease states in humans, come in two discrete forms (i.e., are dimorphic), yet their genetic basis is not caused by a simple single Mendelian genetic factor. The role of genetics and the processes that generate discrete forms from continuous genetic and environmental inputs are not well understood, limiting our ability to predict traits from genomic information and to understand the evolution of these complex traits. The project will develop and use a powerful model system, North American field crickets in the genus Gryllus, to discover the genetic, developmental, physiological, and environmental processes that convert genetic variation and environmental inputs into a dimorphic trait. The project will impact society through improving our ability to predict complex traits across environments, potentially improving disease interventions, enhancing outcomes for selective breeding of domesticated and managed species and populations, and predicting species’ responses to environmental change. Crickets are increasingly used as an alternative food source, and the insights into cricket biology and genomes generated by this project will be a valuable resource for those developing these insects as a sustainable food source. The project will train early career scientists in programs that are broadening participation in the STEM workforce. Finally, the research will be used to generate museum activities that will engage with urban and rural communities to improve science literacy and the appreciation of crickets in the wild and as food. The project will generate foundational and generalizable knowledge on the mechanisms that connect genotype-to-phenotype for dichotomous traits with complex multigenic architecture. The project will develop genomic resources for Gryllus field crickets and use these tools in a phylogenetic framework to generate a mechanistic understanding of how multigenic and environmental variation combines with developmental thresholds to jointly determine discrete dimorphic phenotypes. Multiple species of field cricket are dimorphic for alternative wing morphs, with adults emerging as either long-winged, flight-capable crickets with delayed reproduction or as short-winged, flightless crickets that can reproduce immediately. Previous studies indicate wing dimorphisms in field crickets are classic alternative life-history strategies that are environmentally sensitive and shaped by multigenic variation consistent with the quantitative genetic threshold trait model. The project integrates quantitative, evolutionary, and functional genetic approaches to mechanistically dissect the genomic, developmental, and physiological basis for alternative life-history strategies. The project results will inform prediction of phenotype from genotype generally for complex multigenic dimorphisms, such as protective, trophic, and mating polymorphisms, in addition to threshold traits that impact human disease and breeding of domesticated species. The proposed phylogenetic framework will inform how dimorphic life-history strategies may be maintained, gained, or lost during species radiations. This project is jointly funded by the Enabling Discovery through GEnomics (EDGE) program and the Established Program to Stimulate Competitive Research (EPSCoR). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.