A mechanism for temporary bioadhesion

Abstract

The flatwormMacrostomum lignanofeatures a duo-gland adhesive system that allows it to repeatedly attach to and release from substrates in seawater within a minute. However, little is known about the molecules involved in this temporary adhesion. In this study, we show that the attachment ofM. lignanorelies on the secretion of two large adhesive proteins,M. lignanoadhesion protein 1 (Mlig-ap1) and Mlig-ap2. We revealed that both proteins are expressed in the adhesive gland cells and that their distribution within the adhesive footprints was spatially restricted. RNA interference knockdown experiments demonstrated the essential function of these two proteins in flatworm adhesion. Negatively charged modified sugars in the surrounding water inhibited flatworm attachment, while positively charged molecules impeded detachment. In addition, we found thatM. lignanocould not adhere to strongly hydrated surfaces. We propose an attachment–release model where Mlig-ap2 attaches to the substrate and Mlig-ap1 exhibits a cohesive function. A small negatively charged molecule is secreted that interferes with Mlig-ap1, inducing detachment. These findings are of relevance for fundamental adhesion science and efforts to mitigate biofouling. Further, this model of flatworm temporary adhesion may serve as the starting point for the development of synthetic reversible adhesion systems for medicinal and industrial applications.

Molecular insights into the powerful mucus-based adhesion of limpets ( Patella vulgata L.)

“…While P-vulgata_3 featured nearly all of the conserved domains of SCO-spondin (vWFD, TIL, C8, LDLrA), P-vul-gata_6 had just the repeating TSP-1-like domains in common. As a result of these repeating domains, however, P-vulgata_6 aligned with a small portion of adhesion protein 2 from Macrostomum lignano (QAX24810.1) [54]. P-vulgata_5 was homologous to the settlement-inducing protein complex (SIPC) from barnacles (Megabalanus coccopoma; 91% QC, 27.70% ID; BAM28692.1), both of which contain alpha-2 macroglobulin domains.…”

A phylogenetically informed search for an alternative Macrostomum model species, with notes on taxonomy, mating behavior, karyology, and genome size

“…The free‐living flatworm Macrostomum lignano Ladurner, Schärer, Salvenmoser, Rieger 2005 (Rhabditophora, Macrostomorpha) has emerged as a model for a broad range of research topics (Ladurner, Schärer, Salvenmoser, & Rieger, ), including the biology of aging (Mouton, Grudniewska, Glazenburg, Guryev, & Berezikov, ; Mouton et al, ), bioadhesion (Lengerer, Hennebert, Flammang, Salvenmoser, & Ladurner, ; Lengerer et al, ; Wunderer et al, ), regeneration (Egger, Ladurner, Nimeth, Gschwentner, & Rieger, ; Lengerer et al, ), stem cell biology (Grudniewska et al, ; Ladurner et al, ), and sexual selection (Marie‐Orleach, Janicke, Vizoso, David, & Schärer, ; Schärer, Littlewood, Waeschenbach, Yoshida, & Vizoso, ; Sekii et al, ). This research has led to the establishment of many resources and tools that are crucial for a modern genetic and genomic model, including in situ hybridization (Pfister et al, ), RNA interference (Kuales et al, ; Sekii et al, ), gene expression (Arbore et al, ; Grudniewska et al, ; Lengerer et al, ), genome and transcriptome assemblies (Wasik et al, ; Wudarski et al, ), transgenesis (Marie‐Orleach, Janicke, Vizoso, Eichmann, & Schärer, ; Wudarski et al, ), and a clarification of the phylogenetic context (Janssen et al, ; Schärer et al, ).…”

The free-living flatworm Macrostomum lignano

“…Macrostomum lignano can attach to any natural substrate, followed by controlled detachment [33,34]. This reversible attachment relies on a duo-gland adhesionrelease system which consists of ~ 130 adhesive organs located on the ventral side of the tail plate [33,35].…”

“…Each adhesive organ is comprised of three cell types: an adhesive gland cell, a releasing gland cell, and a modified epidermal cell called the anchor cell. Recent studies revealed a number of adhesion-related transcripts and two large proteins that mediate temporary adhesion of M. lignano [34,36]. Using proteomic data, antibody, and lectin staining, as well as interference of attachment using specific molecules and surfaces, a model for M. lignano attachment and release was proposed [34].…”

“…Recent studies revealed a number of adhesion-related transcripts and two large proteins that mediate temporary adhesion of M. lignano [34,36]. Using proteomic data, antibody, and lectin staining, as well as interference of attachment using specific molecules and surfaces, a model for M. lignano attachment and release was proposed [34]. Overall, a better understanding of M. lignano bio-adhesion could lead to the generation of synthetic equivalents for medical and industrial applications.…”