A DNA barcode reference library for Swiss butterflies and forester moths as a tool for species identification, systematics and conservation.

Butterfly monitoring and Red List programs in Switzerland rely on a combination of observations and collection records to document changes in species distributions through time. While most butterflies can be identified using morphology, some taxa remain challenging, making it difficult to accurately map their distributions and develop appropriate conservation measures. In this paper, we explore the use of the DNA barcode (a fragment of the mitochondrial gene COI) as a tool for the identification of Swiss butterflies and forester moths (Rhopalocera and Zygaenidae). We present a national DNA barcode reference library including 868 sequences representing 217 out of 224 resident species, or 96.9% of Swiss fauna. DNA barcodes were diagnostic for nearly 90% of Swiss species. The remaining 10% represent cases of para- and polyphyly likely involving introgression or incomplete lineage sorting among closely related taxa. We demonstrate that integrative taxonomic methods incorporating a combination of morphological and genetic techniques result in a rate of species identification of over 96% in females and over 98% in males, higher than either morphology or DNA barcodes alone. We explore the use of the DNA barcode for exploring boundaries among taxa, understanding the geographical distribution of cryptic diversity and evaluating the status of purportedly endemic taxa. Finally, we discuss how DNA barcodes may be used to improve field practices and ultimately enhance conservation strategies.

Cytotoxic T cells are preferentially activated in the duodenal epithelium from patients with florid coeliac disease.

Villous atrophy and increased numbers of intraepithelial T cells in duodenal biopsies represent a hallmark of coeliac disease. In the present study, an attempt has been made to define whether cytotoxic cell subsets are activated in situ in the affected mucosa of susceptible individuals early after ingestion of a gluten-containing diet. Duodenal biopsies from 11 patients with coeliac disease who repeatedly underwent endoscopic biopsy after ingestion of individually dosed amounts of gluten were used for immunohistochemistry and in situ hybridization. To identify the cell subsets expressing perforin mRNA and protein, in situ hybridization and FACS analyses were performed on cells isolated from fresh biopsies. Compared with normal mucosa, the number of intraepithelial lymphocytes containing perforin mRNA and protein increased significantly in tissue samples showing moderate or florid coeliac disease and closely paralleled the severity of morphological alteration, whereas the frequency of perforin-expressing lamina propria lymphocytes increased only moderately. Cells isolated from florid biopsies that expressed perforin mRNA and protein were preferentially T-cell receptor (TCR) alphabeta T cells. The increase in both the absolute number and the percentage of lymphocytes expressing perforin mRNA indicates in situ activation of lymphocytes within the epithelial compartment in florid coeliac disease upon ingestion of a gluten-containing diet in patients predisposed to coeliac disease.

Macrophages expressing triggering receptor expressed on myeloid cells-1 are underrepresented in the human intestine.

Triggering receptor expressed on myeloid cells (TREM)-1 is a cell surface molecule on neutrophils and monocytes/macrophages implicated in the amplification of inflammatory responses by enhancing degranulation and secretion of proinflammatory mediators. Macrophages play an important role in the intestinal mucosal immune system, because they are preferentially localized in the subepithelial region. Despite the presence of enormous numbers of bacteria in the colonic mucosa and the close proximity between mucosal macrophages and luminal bacteria, the intestinal mucosa normally displays minimal signs of inflammation. In this study, we show that the resident macrophage population in normal human small and large intestine contains only few TREM-1-expressing macrophages (<10%), whereas the overwhelming majority of monocytes (>90%) and macrophages from lymph nodes or tonsils (>80%) express TREM-1 on the cell surface. These findings were confirmed by FACS analysis and immunostainings of frozen tissue sections. The differential expression of TREM-1 greatly affects the functional capacities of monocytes and tissue macrophages. Although monocytes and macrophages from spleen, lymph nodes, or tonsils show a substantial increase in oxidative burst after TREM-1 cross-linking, no effect is seen in intestinal macrophages. Intriguingly, in contrast to monocytes, intestinal macrophages fail to up-regulate TREM-1 in response to TNF. This refractory state may be induced in intestinal macrophages by the local presence of IL-10 and TGF-beta, because these two immunoregulatory cytokines synergistically down-regulate TREM-1 expression on monocytes in vitro. The absence of TREM-1 expression on lamina propria macrophages is likely to prevent excessive inflammatory reactions, and thus, excessive tissue damage in the intestine.