NSF Postdoctoral Fellowship in Biology FY22: Breaking the Symmetry: Dorsal-Ventral Domain Establishment in the Floral Meristem in Mimulus

Min, Ya, Storrs CT

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2022, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment and Phenotypes. The fellowship supports research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. Flowers that appear similar in shape in both the front and back of the flower are called bilaterally symmetrical. These shape of flower is one of the most common floral forms (e.g. orchids and legumes). During flowering plant evolution, there have been at least 130 independent transitions in to this form, and these transitions are associated with specialized flower-pollinator interactions and the rapid appearance of new plant species. The molecular mechanisms defining this flower arrangement, however, is poorly understood, mainly due to the lack of appropriate functional tools in most systems with bilaterally symmetric flowers. This project aims to address this fundamental question by employing a newly developed model system, the Great Purple Monkeyflower Mimulus lewisii. Results from this project will be important from both developmental and evolutionary perspectives. Moreover, this project will provide molecular lab training opportunities for undergraduate students, workshops and publications to disseminate resources developed for this flower to the broader scientific community, and outreach activities to local communities about the diversity and importance of flowering plants. Although it is well known that differential organ elaboration along the dorsal-ventral (D-V) axis in many taxa is controlled by a developmental program dependent on the CYCLOIDEA (CYC) gene, what establishes the D-V domains at the earliest developmental stage and what activates the expression of CYC specifically in the dorsal domain remain unknown. This project will focus on two M. lewisii mutants with altered CYC expression patterns and will use multiple approaches to characterize the underlying molecular pathways upstream of CYC, including using genetic crosses to dissect the genetic relationships among the key regulatory genes; high resolution live imaging to reveal the spatiotemporal dynamics of gene expression patterns; and co-immunoprecipitation to identify interacting protein partners and downstream target genes. Results from this project are not only significant for understanding how floral symmetry is established at the earliest developmental stages, but also crucial for understanding mechanisms underlying convergent evolution in floral forms. 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.