Resolving the Mollusca Phylogeny using ESTs

C. Dunn (Brown University), G. Giribet (Harvard University), N. Wilson (UCSD)

Most controversy lies on the monophyly of Aplacophora, relationships within Conchifera, the placement of Polyplacophora; common diphyly

Bivalve species included in the project

new dataset for a total of 64 species

ESTs (Expressed Sequence Tags) are a randomly sequenced subset of expressed genes that are derived from messenger RNAs via complimentary DNA (cDNA) libraries

mRNAReverse transcriptase

RNA

cDNA

synthesis of 2nd strand of DNA

dsDNA

Forward Sequence Primer

3’ EST

Reverse Sequence Primer

5’ EST

adaptors conected to the cDNA

Assemblies of raw ESTs into unique transcripts with assembler software

Orthology assignment – gene selection and matrix assembly

Clusters evaluation

Phylogeny inference from nucleotides and AAs matrices

~50,000 reads per taxon

Public data

assign new sequences to old clusters