Coevolutionary Relationships in a New Marine Symbiosis

Marine Biological Laboratory, Woods Hole MA

Investigators

Abstract

Abstract EF-0340538 A grant has been awarded to Dr. Mary B. Saffo of the Marine Biological Laboratory to use morphological (using transmission electron microscopy) and molecular (primarily ssu rDNA) data to describe and determine the phylogenetic position of an enigmatic protist (Nephromyces). Nephromyces was originally described as a chytrid fungus based on light-microscope morphology of some cell types but preliminary data indicates that it may need to be transferred to the Alveolata. The Alveolata is one of the major branches of the protist portion of the Tree of Life. It is a large assemblage including the phyla Ciliophora, Dinoflagellata, and the Apicomplexa but also including many small enigmatic symbionts (often parasites) such as Perkinsus, Haplosporidea, Colpodella and possibly Nephromyces. Phylogenetic relationships among the members of the Alveolata are confusing and it is possible that a better understanding of enigmatic taxa such as Nephromyces may hold the clue to their relationships. Furthermore, the phylogenetic position of the protist will allow Dr. Saffo to begin to address questions about how its symbiosis with its tunicate host and its own bacterial symbionts originated, and how have these three species coevolved.