Dr. Annkatrin Rose

Functional Diversification after Duplication in the FLIP4 Gene Family of Arabidopsis thaliana

Annkatrin Rose, Matthew Cole, Michael T. Judge, K. Bear Reel
Appalachian State University, Boone, NC 28608, USA

The Arabidopsis genome has undergone wide-spread genetic duplication resulting in numerous homologous gene pairs within duplicated chromosome regions. One example is the FLIP4 (Filament-like Protein 4) gene family. In Arabidopsis, this pair consists of two genes in duplicated regions of chromosomes 3 and 5, respectively, while it has been conserved as a single-copy gene in other plant species such as tomato and rice. FLIP4 genes code for acidic proteins of about 50 kDa in size with a C-terminal coiled-coil domain and putative chloroplast envelope localization. Interestingly, knock-out mutants of one of the two FLIP4 genes in Arabidopsis show a pleiotropic phenotype under certain growth conditions, while knock-out mutants of the other gene are indistinguishable from wildtype, and double mutants appear to be lethal. We hypothesize that divergence in gene expression patterns as well as subcellular protein targeting and interactions are contributing to neofunctionalization and the preservation of both members of the FLIP4 gene family after gene duplication in Arabidopsis. To test this hypothesis, we are currently investigating the expression patterns of the two genes through real time PCR and promoter-GUS fusions. The results of these studies will allow us to better understand the functions of the FLIP4 genes in plants, as well as elucidate the mechanisms of diversification and neofunctionalization within this gene family in Arabidopsis.

We would like to thank the Department of Biology, Office of Student Research and University Research Council at Appalachian State University for funding.

Chalk Talk at the 27th Annual Plant Molecular Biology Retreat in Asheville, NC, September 13-15, 2013.