Development of a real-time PCR assay for the detection of the golden mussel ( Limnoperna fortunei, Mytilidae) in environmental samples

ABSTRACT The golden mussel, Limnoperna fortunei, is among the most devastating invasive species in freshwater habitats worldwide, leading to severe environmental disturbances and economic losses. Therefore, management efforts would be greatly improved by methods that efficiently detect and quantify the abundance of the golden mussel in freshwater habitats, particularly in early stages of colonization. In this study, we describe a highly-sensitive real-time PCR assay targeting a 100-bp region of the COI mitochondrial gene of the golden mussel. The method was able to detect as little as 0.225 pg of target DNA. This assay represents an important contribution to surveillance methods, as well as to optimize field measures to contain and manage populations of the golden mussel in its introduced range.

Exon-primed intron-crossing (EPIC) markers as a tool for ant phylogeography

Exon-primed intron-crossing (EPIC) markers as a tool for ant phylogeography. Due to their local abundance, diversity of adaptations and worldwide distribution, ants are a classic example of adaptive radiation. Despite this evolutionary and ecological importance, phylogeographical studies on ants have relied largely on mitochondrial markers. In this study we design and test exon-primed intron-crossing (EPIC) markers, which can be widely used to uncover ant intraspecific variation. Candidate markers were obtained through screening the available ant genomes for unlinked conserved exonic regions interspersed with introns. A subset of 15 markers was tested in vitro and showed successful amplification in several phylogenetically distant ant species. These markers represent an important step forward in ant phylogeography and population genetics, allowing for more extensive characterization of variation in ant nuclear DNA without the need to develop species-specific markers.

A molecular method for the detection of sally lightfoot crab larvae (Grapsus grapsus, Brachyura, Grapsidae) in plankton samples

The decapod Grapsus grapsus is commonly found on oceanic islands of the Pacific and Atlantic coasts of the Americas. In this study, a simple, quick and reliable method for detecting its larvae in plankton samples is described, which makes it ideal for large-scale studies of larval dispersal patterns in the species.

Lethargic crab disease: multidisciplinary evidence supports a mycotic etiology

Although lethargic crab disease (LCD) is causing massive mortalities in populations of the mangrove crab Ucides cordatus of Northeastern Brazil, the identity of its etiological agent was hitherto unknown. In this study we provide robust evidence suggesting that LCD is caused by an anamorph Ascomycota (Fungi). We examined specimens of U. cordatus collected from stocks affected by LCD. Histological and TEM methods detected the presence of hyphae, conidia, and condiophores in several host tissues. Moreover, the abundance of fungal stages is negatively associated with crab health. Finally, DNA was isolated from the fungus and a region of its 18S ribosomal gene was sequenced. Phylogenetic analyses not only confirm the diagnosis of the LCD fungus in crab tissues as an ascomycete, but also suggest a close relationship with members of the subphylum Pezizomycotina.