Développement d’une méthode PCR-SSCP pour caractériser le régime alimentaire des gastéropodes
The diet of terrestrial gastropods is difficult to assess in nature because of their often-nocturnal activity and their small size. Moreover, visual analyzes of digestive contents are problematic because gastropods grind food into small particles, making visual identification unexploitable. Determining the gastropods ‘diet is nevertheless highly relevant because gastropods may have strong ecological and economic impacts. On the one hand, several species are listed endangered or critically endangered. On the opposite, numerous species are considered agricultural pests. The objective is to produce an accurate and inexpensive method to determine the diet of gastropods. More specifically, by using an approach based on PCR-amplified DNA followed by SSCP gels, it was possible to determine taxa diversity before Sanger sequencing, and thus reduce costs. We used Arion fuscus from four old maple forests sites in southern Quebec (Canada) as model to test the method. The 52 individuals’ digestive contents analyzed resulted in a successful PCR amplification and independent DNA extractions from a given individual gave the same SSCP pattern. This method produced reliable results in a few weeks and at a low cost, making it possible to sequence only a few samples to know the plant species consumed by all individuals in the study. Results revealed a low diversity of plants consumed (6 haplotypes). 78.8% of the slugs harvested in spring consumed one and the same species of plant. This method enables the monitoring of plant species consumed by gastropods in conservation and agricultural pest control.
Arion fuscus Sanger SSCP Diet molecular analyzes maple forest