Evolution of novel phenotypes through regulatory small RNAs

Plants and animals display remarkable diversity in the range of colour patterns, from the spots and stripes on butterfly wings to striking pollinator guides on a flower. How does such diversity arise? In a recent breakthrough, we have found that the generation of regulatory small RNAs from inverted duplications plays a key role in the evolution of novel flower colour patterns. These findings, obtained through analysis of wild relatives of the garden snapdragon, Antirrhinum majus, raise several questions: How do inverted duplications generating regulatory small RNAs originate? How do they coevolve with their targets? How general this mechanism is for other colour patterns and traits? The aim of this project is to address these questions through a combination of genetic, molecular, genomic and bioinformatic approaches. The student will obtain genome sequences from a range of wild plant species (related to snapdragons) with diverse colour patterns and analyse the genes controlling flower colour to determine the likely contribution of regulatory small RNAs to phenotypic diversity. These findings will be followed up by inter-crossing closely related species and analysing F2s to determine how the colour genes segregate and influence the expression of small RNAs and their targets. Taken together, the project should provide fresh insights into the origin and role of inverted duplications and regulatory small RNAs in the evolution of phenotypic diversity.