Phylogenetic Analysis of Nuclear, Ribosomal, Mitochondrial, and Chloroplastic DNA in Chlorella and Related Green Algae Species

Abstract

In order to develop a further understanding of the evolutionary relationships between different Chlorella algal strains and related species, methods of algal DNA extraction, PCR, sequencing, and analysis were tailored to our project. With the goal of understanding algal relationships and an intent of affecting algal biofuel production, DNA from multiple regions of algal cells was targeted. Ribosomal DNA including the 18S, ITS1, 5.8S, ITS2, and 28S regions; Chloroplastic DNA (the RuBisCO large subunit coding region); Genomic DNA (the RuBisCO small subunit coding region); and Mitochondrial DNA (Cytochrome C Oxidase subunit I coding region) were picked to be analyzed from each of our algal strains. The comparison of the phylogenetic trees is then being used to determine relationship grouping patterns with increasingly robust trees as more sequencing data is obtained. Further analysis and sequencing of the four regions should give a better understanding of relationships and help to determine the proximity of certain chlorella‐like algal species to one another. Furthermore, extended distance between two strains of the same species provides ground for questioning the nomenclature of certain strains with comparison to their actual genetic composition. Funding provided by NSF‐EPSCoR: 1004–094.