Meeting Abstract
Choanoflagellates, the closest living relatives of animals, are a group of microeukaryotes found ubiquitously in aquatic environments. As the sister group to Metazoa, studying choanoflagellates may provide insight into the origins of animal multicellularity. The choanoflagellate, Salpingoeca rosetta, has an intricate life history and can transition between several unicellular and multicellular cell types. These cell types include attached thecate cells, slow swimmers, fast swimmers, chain colonies, and rosette colonies. Rosette colonies are robust (cannot be easily separated by mechanical force) clusters of at least three cells with organized polarity that develop through serial cell divisions. The complex life history of S. rosetta provides an excellent model to study the transition to multicellularity. However, while many S. rosetta cell types are morphologically distinct, we understand very little regarding the molecular mechanisms underlying these life history transitions; thus, it is necessary to identify molecular markers for distinct cell types in order to characterize these transitions. We tested a myriad of antibodies to identify markers that either differentially stain or localize within single cells and rosettes. Based on our initial screen, the following candidates seem promising for further investigation: procollagen, maIE, and pMLC.
