UCT Researchers Identify 2 Genes That Set Butterfly Lily Flower Handedness
Updated
Updated · news.uct.ac.za · Jul 31
UCT Researchers Identify 2 Genes That Set Butterfly Lily Flower Handedness
2 articles · Updated · news.uct.ac.za · Jul 31
Summary
A Science paper from UCT and international collaborators shows how butterfly lilies determine whether each flower develops left- or right-oriented reproductive parts, resolving a puzzle Darwin noted shortly before his death.
DNA comparisons across hundreds of plants in four Wachendorfia species and Barberetta aurea isolated a DNA segment found only in right-oriented plants, leading researchers to two linked genes—YUC-R and miR156.
Experiments on developing buds showed those genes switch the default left-oriented program before the style and stamen bend, while natural mutants with defective YUC-R or miR156 flipped those structures in predictable ways.
An accidental upside-down positioning of a flower bud revealed gravity as a directional cue, with the developing flower reversing style and stamen orientation instead of continuing normal growth.
The findings connect genes, environmental signals and development in left-right symmetry breaking, a basic biological question that extends beyond these South African plants.