PhD student (Adv. Gerhard Steiner, Janek von Byern)

Unit for Integrative Zoology, Department of Evolutionary Biology
University of Vienna

Abstract

Bioadhesives fulfil many different needs, for example animals use them for attachment, predation or as defence. Since 500 million years various adhesive gland systems and glue types have evolved, perfectly adapted to the needs of the individual organism. Although over 100 marine and terrestrial species are known today to produce glue, only a few of them have been characterized in detail so far.

The freshwater gastropod Latia neritoides is an endemic species of New Zealand’s Northern Island and releases a luminescent and sticky mucus when threatened by predators. While some information has been collected on the luminescent components of this defence mucus, less is known about the adhesive mechanisms.

This project aims to perform a detailed chemical analysis of the defence mucus and characterize its underlying gland system. The mucus and its composition are investigated chemically (by histochemistry, lectin affinity tests, proteomics), the gland system currently through 3D-reconstruction.

In particular, the proteomic data indicate that defence and trail mucus vary in view of the number and molecular size of the proteins. Determined by SDS-PAGE, different protein patterns appear for the defence and trail mucus. Histochemically, minor differences between both mucus types are detectable, both contain sulfated and carboxylated mucosubstances and lipids. Lectin binding tests display the presence of α-linked mannose (reactive to lectin ConA) and N-acetylglucosamines (reactive to lectin VVL) in both mucus types, while α-linked fucose (lectin UEA I) is only present in the trail mucus. These reactivities are also found when electrophoretically separated proteins are transferred onto nitrocellulose; with this method positive staining can be attributed to specific bands and help to further characterize the proteins.

According to present results the mucus composition of the trail mucus of Latia appears dissimilar to that of Neritina pulligera, another limnic snail.