Diversity and dynamics of marine haptophytes as revealed by 454 pyrosequencing

Haptophytes are microalgae and a major component of marine plankton communities. Our aim is to provide new knowledge on the diversity and distribution of haptophytes below the genus-level, and how this is affected by environmental factors. We have developed and tested methods for analysing diversity using 454-pyrosequencing, We designed haptophyte-specific rDNA primers and constructed haptophyte databases and phylogenies for taxonomic assignation. We sequenced an artificial haptophyte community and compared the diversity and relative abundances from DNA and RNA/cDNA using various rDNA primers, and different programs to 18 remove errors from sequence data. We applied 454-pyrosequencing to samples from six European coastal sites and seasonal samples from Oslofjorden, and combined this with electron microscopy. We propose a strategy to more accurately depict the haptophyte diversity using 454-pyrosequencing and present results using this strategy.