Evolutionary Developmental Biology (Evo-Devo)
Preston, Jill , Hileman, Lena .
Candidate gene expression provides insights into the evolution of Commelinaceae inner tepal symmetry.
Flower bilateral symmetry has evolved multiple times independently across angiosperms, and is correlated with increased pollinator specialization and speciation rates. Functional analyses in distantly related core eudicots implicate independent recruitment of class II TCP genes in the evolution of flower bilateral symmetry. By contrast, available evidence suggests that monocot flower bilateral symmetry might have evolved through changes in B-class homeotic MADS-box gene function. In order to test the non-exclusive hypotheses that changes in TCP and B-class gene function underlie flower symmetry evolution in the monocot family Commelinaceae, we compared expression patterns of TEOSINTE BRANCHED1 (TB1)-like, DEFICIENS (DEF)-like, and GLOBOSA (GLO)-like genes in morphologically distinct bilaterally symmetrical flowers of Commelina communis and C. dianthifolia, and radially symmetrical flowers of Tradescantia pallida. Expression data demonstrate that both TB1-like and DEF-like genes are asymmetrically expressed in inner tepals of C. communis. However, similar data for C. dianthifolia and T. pallida indicate that only DEF-like gene expression is strongly correlated with differentiation of the ventral inner tepal. Together with other studies, this suggests parallel recruitment of B-class genes in the independent evolution of petal bilateral symmetry in monocots, and a complex history of CYC/TB1-like gene evolution across angiosperms.
Log in to add this item to your schedule
2 - University of Kansas, Ecology and Evolutionary Biology, 1200 Sunnyside Avenue, Lawrence, KS, 66045, USA
flower bilateral symmetry
Presentation Type: Oral Paper:Papers for Topics
Location: Lindell D/Chase Park Plaza
Date: Wednesday, July 13th, 2011
Time: 9:15 AM