Comparative transcriptome analysis of the intertidal barnacles, Amphibalanus amphitrite and Tetraclita japonica formosana: interspecific variation in settlement-related genes and barnacle cement proteins

Illumina’s Solexa sequencing is applied to examine settlement-related genes and cement proteins in two intertidal barnacles, Amphibalanus amphitrite and Tetraclita japonica formosana. 45,180,306 and 52,513,742 raw sequence reads were generated, and 97,832 and 63,422 unigenes were further assembled, respectively. 20,319 and 17,239 genes were annotated with unique NCBI non-redundant (Nr) protein accession numbers. Transcriptome of these two species shares 12,031 genes and oxidative stress-related genes tend to have higher expression in Tetraclita probably due to this species lives in higher levels of the intertidal. Settlement-related gene homologues including settlement inducing protein complex (SIPC), lectins, and barnacle cypris larva-specific genes (BCS) were observed in both species. However, 19K-, 20K- and 100K- cement protein homologues were only found in Amphibalanus, probably due to structural differences in the bases of the two species examined. Glycine-rich proteins or other unidentified cement proteins might substitute these balanid cement proteins in Tetraclita.