Gene-trap reporter gene expression from the prolifera gene is localized in the nuclei of root cells. Prolifera encodes a homolog of the yeast DNA replication gene CDC47.

We are investigating stem cell function in plants by characterizing asymmetric leaves1, bellringer, and argonaute in Arabidopsis and ramosa 1 in maize. ARGONAUTE has an important role in RNAi, and small RNA appears to act as a signal to specify leaf polarity.

Our research in plant genomics, funded by the National Science Foundation, includes studies on polyploidy, chromatin organization, DNA replication and chromatin profiling, and maize inflorescence architecture. We are collaborating with New York University, the American Museum of Natural History, and the New York Botanical Garden to investigate the origin of seed plants by studying the genomes of primitive gymnosperms.

We have found that most DNA methylation in plant genomes is restricted to transposons and repeats, and we have developed methods for very rapidly sequencing plant genomes based on this observation. We maintain an efficient system for site-selected transposon mutagenesis in maize as a knockout service to the community. We also maintain a collection of 40,000 Arabidopsis gene trap and enhancer trap transposon lines, which along with phenotypic and expression data, are made available to the public via TRAPPER, an interactive database and ordering system (http://genetrap.cshl.org).

Selected Publications