EAPSI:Investigating the Origin and Evolution of Locomotion in the Microalgae Diatoms

Beals Jennifer M, Lansdale PA

Investigators

Abstract

Diatoms are a diverse group of microalgae responsible for approximately one-third of atmospheric oxygen and are an important source of essential fatty acids for both aquatic organisms and for humans. They are abundant in oceans, lakes and rivers and live either suspended in the water column or attached to other aquatic substrates; some groups also have developed motility. Recent research with diatoms has focused on their use for both food supplements and for biofuels because of both the favorable fatty acid and lipid content, and their fast growth rate. As this research is relatively new, attempts have been made to identify commercially useful taxa based on their evolutionary relationship to other useful species. This study aims to understand the origin and evolution of the first group of motile diatoms and will be conducted with Dr. Shigeki Mayama at Tokyo Gakugei University, Japan, who is the world?s expert in this group of diatoms, and also an expert in diatom growth techniques that are essential to the study. While significant effort has been made conducting DNA and evolutionary studies of other diatom lineages, very little effort has been made to sequence the DNA and understand the evolution of the first motile group. The origin and evolution of the diatom raphe, which is responsible for motility, will be investigated by constructing morphological and molecular phylogenies of early raphid and pre-raphid diatoms. Diatoms within the subclass Eunotiophycidae are accepted as the first raphid diatoms, however the first raphid genus is still a point of contention. Lineages that led to the raphid diatoms have also not yet been identified. The researcher will conduct field studies in Japan to gather taxa to include in analyses. Collaboration with Dr. Mayama, who is the world?s expert in Eunotia morphology and culturing techniques, will be an essential component of the project. This expansion of molecular and morphological knowledge will be essential to the study, as there is molecular sequence data in GenBank for less than 1% of the described Eunotia species, and no data at all for any other genera within the subclass. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.