AN –OMIC APPROACH TO EXPANDING THE FUNCTIONAL UNDERSTANDING OF THE ACORN BARNACLE Amphibalanus amphitrite

The acorn barnacle Amphibalanus (=Balanus ) amphitrite is an established hard foulant with a  global distribution in  tropical  and sub-tropical  marine environments.  Due to the robust nature of  A. amphitrite in both the wild and in laboratory conditions, it has been studie d extensively to understand several aspects of acorn barnacle function including settlement and growth , with particular attention to  the formation  and composition of adhesives at the substrate interface.

O ur research group has been expanding our knowledge of the development of the adhesive interface, relying  on several techniques ranging from con-focal microscopy to mass spectrometry (MS) . The latter has relied heavily on a transcript library that enables spectral assignment and, therefore, proteomic analysis . This has allowed us to identify a wide range of proteins and enzymes at the adhesive interface. The  general  protein identification scheme via MS (Fig. 1) highlights  the predicted and experimental approaches to gather spectra. O ne  critical  caveat of this scheme for  A. amphitrite is the genomic information  available is limited to transcripts gathered from one tissue rather than a completely sequenced genome . As a consequence , it is not uncommon that up to 80% of peptide and potential protein hits are unidentified. This presents a major bottleneck to advancing our understanding of key acorn barnacle functions.

Here, we present  preliminary results on sequencing the genome of  A. amphitrite  using a combination of long- and short-read next-generation sequencing technology and  discuss  the  challenges  associated with collection of high quality genomic DNA . Building upon our existing transcript and protein knowledge, w e demonstrate how complementary gene and transcript data sets  are powerful tools  to  help unravel key  functional  mechanisms  of  A. amphitrite  through an expanded identification of proteins associated with the formation of the adhesive interface and the adhesive itself. Collectively, these -omic results will deepen our understanding of acorn barnacles, which, as sessile crustaceans, are one of nature's more unusual creatures possessing a robust  and durable  underwater  adhesive.