By Julia Karow
As part of a symbiont genome project, China's sequencing center BGI and several US research groups plan to sequence and analyze the genomes of the green sea slug Elysia chlorotica and its food source, the algae Vaucheria litorea.
The two species are interconnected in that the sea slug sequesters chloroplasts from the algae inside its cells, allowing it to generate energy by photosynthesis. Previous studies have shown that the slug genome contains more than 10 genes originating from the algae genome that are involved in chlorophyll synthesis and the carbon-fixing cycle.
The study, which also involves researchers at the University of Florida and at the University of Maryland at College Park, is part of BGI's recently launched project to sequence 1,000 plant and animal reference genomes over the next two years (see In Sequence 1/12/2010).
BGI researchers plan to sequence the two genomes on the Illumina platform and will provide the bioinformatics analysis. The timeline for the project, which has an estimated budget of $500,000 and is "fully supported through BGI's internal fund," is about six months, according to Bicheng Yang, a researcher at BGI.
Sequencing for the algae has already begun, and will start shortly for the sea slug. The size of the two species' genomes is currently unknown, Yang said. The sea slug Aplysia, the most closely related species to E. chlorotica that has already been sequenced, has a 1.8- to 2-gigabase genome.
By comparing the genomes of the green sea slug and the algae, the researchers hope to identify all genes required to sustain active chloroplasts in a host cell. They also want to better understand the mechanism of gene transfer between two species. In addition, the project is expected to be valuable to evolution, developmental biology, and systematics.