EDGE CMT: Evolutionary developmental systems genetics of obligate sterility in ants

Texas Tech University, Lubbock TX

Investigators

Abstract

A major goal of Biology is to understand the links between genomes and development and how evolution has tinkered with these mechanisms to produce the diversity of life. Ants provide powerful study systems for exploring these and related topics because they show striking diversity within and between species. A defining feature of ant societies is the presence of a reproductive caste system where some individuals called queens specialize on reproduction and other individuals called workers specialize on other tasks. In most species, workers possess reduced reproductive organs and are capable of reproduction under certain circumstances (e.g., queen death), but in other species, workers completely lack reproductive organs. Such obligate worker sterility has evolved at least 14 times across ants, yet little is known about the molecular mechanisms regulating the expression of this obligate sterility or whether the mechanisms are the same across each of the independent origins of sterility. The overall goal of this research is to elucidate the mechanisms underlying the expression and evolution of obligate sterility in ants and to further validate the effects of genes influencing the development of sterility in fruit flies. Our research may provide novel insight into conserved genetic pathways regulating animal reproduction and reproductive health. Further broader impacts of the research will be training students and researchers in approaches to study the genetic basis and evolution of development, working to improve public understanding of evolution and development, and working to increase student participation in science. A major goal of Biology is to understand the mechanisms linking genomes to phenotypes and how evolution generates and tinkers with these regulatory mechanisms to produce the diversity of life. One striking phenotype is the presence of an obligately sterile worker caste in social insects, which has evolved at least 14 times in ants, yet little is known about the underlying regulatory networks and whether this convergent phenotypic evolution involves convergent or parallel molecular evolution. The overall goal of this research is to use an integrative approach to elucidate the gene regulatory networks underlying the expression and evolution of obligate sterility in ants. Ants provide a rare opportunity to study how infertility and sterility evolved within the context of their societies, connecting individual germline loss to colony-level gain of a sterile worker caste. The germ-soma distinction within organisms is fundamental to multicellular life, and germline sequestration is a fundamentally important step in animal development. This research may contribute to understanding general principles and molecular pathways associated with animal development and the origin of cell types. Moreover, the research may provide novel candidate genes and pathways regulating a range of complex phenotypes associated with reproduction, reproductive health, to be further studied in model organisms. Further broader impacts of the grant include training students and postdoctoral researchers in approaches to study the genetic basis and evolution of development, working to improve public understanding of evolution and development, and working to increase student participation in STEM fields. 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.