Comparative analysis of stalked and acorn barnacle adhesive proteomes

Abstract

Barnacles interest the scientific community for multiple reasons: their unique evolutionary trajectory, vast diversity and economic impact—as a harvested food source and also as one of the most prolific macroscopic hard biofouling organisms. A common, yet novel, trait among barnacles is adhesion, which has enabled a sessile adult existence and global colonization of the oceans. Barnacle adhesive is primarily composed of proteins, but knowledge of how the adhesive proteome varies across the tree of life is unknown due to a lack of genomic information. Here, we supplement previous mass spectrometry analyses of barnacle adhesive with recently sequenced genomes to compare the adhesive proteomes of Pollicipes pollicipes (Pedunculata) and Amphibalanus amphitrite (Sessilia). Although both species contain the same broad protein categories, we detail differences that exist between these species. The barnacle-unique cement proteins show the greatest difference between species, although these differences are diminished when amino acid composition and glycosylation potential are considered. By performing an in-depth comparison of the adhesive proteomes of these distantly related barnacle species, we show their similarities and provide a roadmap for future studies examining sequence-specific differences to identify the proteins responsible for functional differences across the barnacle tree of life.

Adhesive Materials Inspired by Barnacle Underwater Adhesion: Biological Principles and Biomimetic Designs

“…In this view, the cp68k identified by Kamino (2006) may be a cp43k-like protein for their similar amino acid compositions. Several latest omics investigations further confirmed that these different types of BCPs are widespread in different barnacle species ( Domínguez-Pérez et al, 2021 ; Lin et al, 2021 ; Schultzhaus et al, 2021 ). Notably, apart from these major BCPs, there remains a trace amount of other components such as enzymes and small molecules in barnacle cement, which have not been fully characterized yet.…”

A living conductive marine biofilm engineered to sense and respond to small molecules

“…For proteolytic digestion with trypsin, 60 cycles of PCT were conducted at 45°C, 45 kpsi for 50 seconds, with 10-second pauses between cycles. Liquid chromatography, tandem mass spectrometry (LC-MS/MS) was performed on a Orbitrap Fusion Lumos Tribrid mass spectrometer coupled to an Ultimate 3000 nanoRSLC system (Thermo Scientific, Waltham, MA, USA), as previously described 54-55 . Mass spectrometry data were transformed and raw data extracted into peak lists via in-house scripting 56 .…”

Faint chemical traces of conspecifics delay settlement of barnacle larvae

“…Although it remains to be confirmed that WSP exists in seawater, these findings suggest that WSP is released into the environment. WSP was also detected from a stalked barnacle, Pollicipes pollicipes (Schultzhaus et al, 2021), suggesting that a phylogenetically wide variety of barnacles use WSP to attract conspecific cyprids. Recent studies indicate that there are several homologs of WSP (So et al, 2017;Abramova et al, 2019;Schultzhaus et al, 2019;Schultzhaus et al, 2020;Schultzhaus et al, 2021).…”

“…Another pheromone, WSP, purified from adults of A. amphitrite diffuses into seawater when embedded in an agarose gel, suggesting that it attracts cyprids on a relatively larger spatial scale (Endo et al, 2009;Clare, 2010). In addition, WSP was identified from cement of adult A. amphitrite (So et al, 2017;Schultzhaus et al, 2019;Schultzhaus et al, 2020;Schultzhaus et al, 2021), which indicates that WSP exists in the adhesive layer of adult barnacles. Although it remains to be confirmed that WSP exists in seawater, these findings suggest that WSP is released into the environment.…”