Towards Understanding Mechanisms of mRNA Localization in Plants.

University Of Washington, Seattle WA

Investigators

Abstract

The spatial organization of information is emerging as a critical factor in understanding many aspects of cell and developmental biology. How do organisms know how and where to make a top, bottom, left and right during development? The green algal unicell, Acetabularia or The Mermaid's Wineglass, is a classical developmental model that will be used in this project. Acetabularia grows to an enormous adult length of 4 cm as a single cell, progressing through several morphologically complex stages. This research will begin to describe how protein-coding information, in the form of messenger RNAs, are moved to their correct subcellular locations during development. The correct spatial placement of these messenger RNAs underlies the protein gradients that ultimately dictate morphological specializations. To define the spatial distribution of mRNAs, ~1000 gene tags or "ESTs" from juveniles or adults will be arrayed on a gene chip and probed with mRNA isolated from different regions of this giant cell. Next, a few genes that array analysis suggests may co-localize will be tagged with a fluorescent marker and microinjected back into the unicell. Where, how and how fast these genes and pieces of them move will be followed with video microscopy. Movements of fluorescent-mRNAs in intact, wounded, enucleated or amputated cells will be compared. Classic inhibitors will test if the "highway" on which these mRNAs move is indeed the cellular cytoskeleton. This research will impact understanding of the spatial organization of RNA in all plant cells, and provide an interesting comparison to animal cells that have solved the same problem in different ways. Human resources will be developed by support of students. Public outreach will be enabled by a 4-color brochure about RNA biology that will be created and distributed to teachers and K-12 students.