Localisation of antifreeze proteins in Rhagium mordax using immunofluorescence

TL;DR

This study used immunofluorescence to locate antifreeze proteins in Rhagium mordax larvae, revealing their presence year-round and seasonal distribution changes in cuticle and gut tissues.

Contribution

It demonstrates the seasonal localization of antifreeze proteins in beetle larvae using immunofluorescence, suggesting continuous AFP production and dynamic tissue distribution.

Findings

AFP presence in larvae year-round

Seasonal redistribution of AFPs in tissues

AFP activity in cuticle, gut lumen, and epithelium

Abstract

Larvae of the blackspotted pliers support beetle, Rhagium mordax, express antifreeze proteins in their haemolymph during temperate climate winter. It is believed that they also express antifreeze proteins in their cuticle as a means of preventing inoculative freezing. Larvae of Rhagium mordax were collected during winter (March) and summer (May) of 2011. Larvae were fixated, embedded in paraffin wax, sectioned on a microtome, incubated with custom made anti-AFP antibodies and isualised on a fluorescence microscope. The larvae of both winter and summer showed AFP activity in their cuticle, gut lumen and -epithelium. Due to the long synthesis process of AFPs, the larvae contain them all year round. The distribution of these AFPs change during summer, possibly relocating to vesicles in the cuticle and gut lumen/epithelium.