Date of Award

Fall 2012

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)


Biological Sciences

Committee Chair

Timothy McLean

Committee Chair Department

Biological Sciences

Committee Member 2

Glenmore Shearer

Committee Member 2 Department

Biological Sciences

Committee Member 3

Mohamed Elasri

Committee Member 3 Department

Biological Sciences


When algal cells proliferate and accumulate in marine and fresh water systems, they form algal blo'oms. The majority of these blooms are beneficial, but a significant number are detrimental and are known as harmful algal blooms (HABs). A number of negative effects, including closing of recreational beaches and economic loss, are observed during HABs. Predictably, the longer a bloom persists, the greater its effects on human, environmental and economic health. Karenia brevis, a mixotrophic dinoflagellate, forms HABs, and blooms caused by this organism have been known to remain several months after formation. For these reasons, research has been conducted to discover those factors that are responsible for the formation, maintenance and terminations of K.brevis blooms. These factors, whether man-made (e.g. eutrophication) or naturally occurring (e.g. aquatic fronts), have been and continue to be extensively investigated. As part of an effort to find molecular or genetic determinants that control K. brevis biology, it was discovered that these cells express a number of anti-sense RN As. For the first time in K.brevis, I have confirmed the expression of targeted anti-sense RNAs (asRNAs) and characterized their sequences. We have developed a model in which the expression of asRNAs leads to the formation of double-stranded RNAs (dsRNA). I have immunofluorescence data to support the presence of dsRNA in K. brevis cells. We hypothesize, based on the known functions of asRNAs in other systems, that the presence of asRNAs (and hence dsRNAs) helps to regulate gene expression at a post-transcriptional level.