| Abstract Detail
Evolutionary Developmental Biology (Evo-Devo) Wu, Cheng-Chiang [1], Kramer, Elena M [2]. Functional Evolution of Floral Homeotic Genes in the Eudicots. Transcriptional regulatory networks control the development and biochemistry of organisms. Many of these networks have evolved through extensive duplication of transcription factor modules, often associated with diversification of protein-protein interactions. However, the evolutionary divergence of protein interactions among phylogenetically-related taxa is poorly studied in plants. The ABCE class genes of MADS-box transcription factors, which can form dimers or multimers and determine floral organ identity in angiosperms, constitute a unique system to study the functional evolution of genetic modules. Phylogenetic analyses suggest that coincident duplication events occurred in the APETALA1 (AP1), APETALA3 (AP3), AGAMOUS (AG), and SEPALLATA (SEP) lineages of MADS-box family transcription factors in close association with the emergence of the core eudicot clade. This cluster of duplications is also correlated with frameshift events in the coding regions of the resultant euAP3 and euAP1 orthologous lineages, resulting in lineage-specific motifs at the C-terminal end that may influence the formation of higher order protein complexes. However, little is known about the expression patterns and protein interactions of these genes from taxa close to the duplication events. We have identified homologs of the AP1, AP3, AG, and SEP lineages, as well as the PISTILLATA (PI) lineage, from Meliosma dilleniifolia (Sabiaceae), which lies close to and before the duplication events, and Corylopsis sinensis (Hamamelidaceae), which arose after the duplications. Expression studies using RT-PCR and in situ hybridization are providing insight into what protein interactions are possible in these taxa. We are also developing in vivo biochemical approaches to analyze potential protein-protein interactions and thereby illuminate the evolution of higher order protein complex formation among floral MADS box proteins. These studies will shed the light on the functional diversification of transcription regulatory modules following gene duplication.
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1 - Harvard University, Organismic and Evolutionary Biology, 16 Divinity Ave, Biolabs 1112
, Cambridge, MA, 02138, USA
2 - Harvard University, Organismic and Evolutionary Biology, 16 Divinity Ave, Biolabs 1109
, Cambridge, MA, 02138, USA
Keywords:
gene duplication
MADS-box gene
eudicots.
Presentation Type: Poster:Posters for Topics
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P70005
Abstract ID:1649 |
