Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

Cote, Erin [1], Galimba, Kelsey [1], Di Stilio, Veronica S [1].

Jumping genes and double flowers: An active MuLE transposon underlies double flower varieties of Thalicturm thalictroides.

The first floral mutations ever documented, double flowers have been prized for centuries for their beauty. The double mutant variants ‘Shoaf’s Double’ and ‘Cameo’ are found in Thalictrum thalictroides, a member of the buttercup family. We set out to determine the genetic mutation underlying this desirable phenotype. We predicted that a mutation in a C-class floral organ identity gene would cause the homeotic transformation (conversion of one organ type to another) of stamens and carpels to petalloid sepals in this species. C-class genes are also involved in floral determinacy, the termination of floral organ growth, which is why double flowers appear to have a second flower nested inside the first. As expected, the expression of the C-class gene ThtAG1 was greatly reduced in our mutants. Finding no changes in the coding region from wild type, we further investigated the entire genomic locus, where we found evidence of the action of a transposable element in both mutants. In ‘Shoaf’s Double’ a Mutator Like Element (MuLE) has inserted itself into a regulatory intron of TthAG1, disrupting its function. In ‘Cameo’ a ‘footprint’ at the exact same place in the sequence indicates that the same element may have jumped out, deleting a section of the intron. We hypothesize that the double phenotype in ‘Cameo’ is likely due to the accumulation of mutations before the MuLE jumped out. Since the MuLE’s transposase is expressed in ‘Shoaf’s Double’ (but not in wildtype), these results illustrate the rare case of an autonomous transposable element underlying a regulatory mutation that results in a visible phenotype. We hope that our work will provide insight into the genetic basis for the double phenotype of popular commercial flowers such as roses, camellias and carnations.

1 - University of Washington, Biology, Box 351800, Seattle, WA, 98195, USA

Keywords:
homeotic mutants
transposable element
ABC model
AGAMOUS
C Class mutant
Ranunculaceace
meadow rue.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Eyrie/Boise Centre
Date: Monday, July 28th, 2014
Time: 5:30 PM
Number: PEV002
Abstract ID:181
Candidate for Awards:None