Molecular and Genetic Characterization of the REM Gene Family of Arabidopsis

Lindsay V. Clark
Dartmouth College

The genome of Arabidopsis thaliana, a small dicotyledonous plant in the mustard family, contains a family of 43 genes known as the REM genes, so named for their homology to the BoREM1 gene, which is expressed preferentially in the reproductive meristem of Brassica oleracea. One unusual feature of this gene family is that the genes are clustered; nine REM genes are clustered in a 35 kb region of chromosome 4 and five REM genes are clustered on chromosome 2. Single knockouts of genes in the chromosome 4 cluster do not result in observable growth or developmental phenotypes. At present, the function of the REM gene family is poorly characterized. Several years ago, the Jack lab generated a large collection of enhancer trap lines in Arabidopsis. I am interested specifically in one of these lines, line 21, which exhibits a shoot apical meristem expression pattern. Line 21 contains a T-DNA insertion between REM3 and REM4, two genes in the chromosome 4 REM gene cluster. We have undertaken a mutagenesis experiment to generate deletions of the REM genes in the chromosome 4 cluster. We hope that multiple gene deletions within the cluster will result in a growth or developmental phenotype. My project thus far has involved mutagenizing pollen from enhancer trap line 21, crossing it into wild-type plants, identifying putative deletion lines by loss of the T-DNA enhancer trap staining pattern, and characterizing putative deletion lines via Southern blotting and PCR.