Evolutionary Developmental Biology (Evo-Devo)
Bartlett, Madelaine , Whipple, Clinton .
The evolution of DEF-GLO heterodimerization in the grasses.
The B class MADS box genes DEFICIENS/APETALA3 (DEF/AP3) and GLOBOSA/PISTILLATA (GLO/PI) play key roles in specifying second and third whorl floral organ identity. DEF and GLO are transcription factors that, like other floral organ identity genes, bind DNA as part of multimeric protein complexes. GLO and DEF orthologs from the grasses Oryza and Zea, as well as from the eudicots Antirrhinum, Arabidopsis, Petunia, Papaver, and Aquilegia, bind DNA as obligate heterodimers in vitro. In a number of earlier diverging monocots, however, B class homodimers were found to be capable of binding DNA. In Lilium, GLO homologs form functional homodimers while in Phalaenopsis both DEF-like and GLO-like homodimers are capable of binding DNA in vitro. Additionally, a GLO ortholog from the close grass relative Joinvillea can bind DNA both as a homodimer and as part of a DEF-GLO heterodimer. In addition, it has been demonstrated that B class proteins from the gymnosperm Gnetum form homodimers capable of binding DNA. Taken together, these results imply that the obligate DEF-GLO heterodimerization relationship evolved separately in the eudicots and in the monocots from ancestral homodimerization. We present results from experiments exploring the convergent evolution of this protein-protein interaction in the grasses.
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1 - Brigham Young University, 401 WIDB, Provo, UT, 84602, USA
Presentation Type: Oral Paper:Papers for Topics
Location: Lindell D/Chase Park Plaza
Date: Wednesday, July 13th, 2011
Time: 10:15 AM