DNA extracted from faeces as a source of information about endemic reindeer from the High Arctic: detection of Shiga toxin genes and the analysis of reindeer male-specific DNA

Abstract

DNA extracted from faeces may be a valuable source of information about the animal itself, as well as its microflora. An isolated reindeer population from Svalbard (Rangifer tarandus platyrhynchus) was tested for the presence of Shiga toxin encoding genes in the collected faecal samples. Even though the reindeers were not interacting with any other ruminants, which are considered to be a major reservoir of Shiga toxin containing bacteria, the stx1 gene was detected in 9 out of 10 tested samples, and the stx2 subtype c was found in five tested samples. This is an exceptionally high proportion, especially in the case of stx1, when compared to those observed in semi-domesticated or wild cervid populations in less remote locations. Distribution of the investigated genes in a small, local population indicates a different pattern of transmission, which seems to favour bacteria carrying the stx1 genes over those carrying the stx2 genes. The overall high percentage of animals with microbiota containing the stx genes suggests an important role of these genes in such an extreme environment for either hosts or their gut bacteria. Additionally, male-specific DNA found in the faeces was isolated in order to establish a given animal’s sex. PCR based on two pairs of primers, DBY7 and DBY8 gave the expected length of product characteristic for Y chromosome. The results of molecular sexing were consistent with field observations.