Differentially Expressed Transcription Factors in the Marine Alga Emiliania Huxleyi

Emiliania huxleyi (E. huxleyi) is a unicellular phytoplankton belonging to the phylum Haptophyta with unique calcium carbonate exoskeletons called coccoliths. E. huxleyi plays an important role in global biogeochemical cycling through carbon fixation during photosynthesis and biomineralization. Though the importance of E. huxleyi to the biogeochemistry of ocean environments is well understood, the molecular mechanisms behind the production of their calcium carbonate outer shells is not. To uncover more information on this process, identification of genes and proteins associated with coccolith production is critical. Coccolithogenesis is a complex process that necessitates a tight and precise control of the genes that are related to biomineralization. The hypothesis herein is that this control is imposed by specific transcription factors and transcription factor regulators. The Multifinder computer software has previously been used reveal putative transcription factor binding sites that are believed to be involved in regulating the expression of genes linked with biomineralization processes. This work aims to use molecular techniques to validate the Multifinder data. Protocols to conduct nuclear isolation and electrophoretic mobility shift assay (EMSA) with E. huxleyi cells were created to show binding between protein extracts from isolated nuclei and oligonucelotides synthesized from data corresponding to the transcription factor binding sites obtained from Multifinder analyses. Further analysis into transcription factor families in E. huxleyi was also conducted using phylogenetic analysis to reveal the relationship between members of the expanded MYB and AP2 transcription factor families in E. huxleyi. This information taken together will lead to a greater understanding of the process of transcriptional regulation and, perhaps biomineralization, in the microalgae E. huxleyi.