Compartmentalization of mRNAs in the giant, unicellular green algaeAcetabularia acetabulum

Acetabularia acetabulum is a single-celled green alga previously used as a model species for studying the role of the nucleus in cell development and morphogenesis. The highly elongated cell, which stretches several centimeters, harbors a single nucleus located in the basal end. Although A. acetabulum historically has been an important model in cell biology, almost nothing is known about its gene content, or how gene products are distributed in the cell. To study the composition and distribution of mRNAs in A. acetabulum , we have used quantitative RNA-seq to sequence the mRNA content of four sections of adult A. acetabulum cells. We found that although mRNAs are present throughout the cell, there are large pools of distinct mRNAs localized to the different subcellular sections. Conversely, we also find that gene transcripts related to intracellular transport are evenly distributed throughout the cell. This distribution hints at post-transcriptional regulation and selective transport of mRNAs as mechanisms to achieve mRNA localization in A. acetabulum .