Sean Williams John Prosser

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DNA barcoding protocols require the linkage of each sequence record to a voucher specimen that has, whenever possible, been authoritatively identified. Natural history collections would seem an ideal resource for barcode library construction, but they have never seen large-scale analysis because of concerns linked to DNA degradation. The present study(More)
The table grape variety "Waltham Cross" was infected with Leafroll and Shiraz Disease. To reveal specific viruses that are associated with the diseased plants, we used an RT-PCR-based strategy to determine partial genome sequences of these viruses. Upon cloning and sequencing of the RT-PCR products, we detected seven groups of viral variants that are(More)
How networks of ecological interactions are structured has a major impact on their functioning. However, accurately resolving both the nodes of the webs and the links between them is fraught with difficulties. We ask whether the new resolution conferred by molecular information changes perceptions of network structure. To probe a network of antagonistic(More)
Despite the contribution of DNA barcoding towards understanding the biodiversity and distribution of species, the success of COI amplification has been quite variable when it comes to freshwater zooplankton (Elías-Gutiérrez & Valdez-Moreno 2008; Jeffery et al. 2011). Some genera of microcrustaceans seem to be more difficult to amplify than others. For(More)
In this study, we evaluated the efficacy of various primers for the purpose of DNA barcoding old, pinned museum specimens of blackflies (Diptera: Simuliidae). We analysed 271 pinned specimens representing two genera and at least 36 species. Due to the age of our material, we targeted overlapping DNA fragments ranging in size from 94 to 407 bp. We were able(More)
Although nematodes are one of the most diverse metazoan phyla, species identification through morphology is difficult. Several genetic markers have been used for their identification, but most do not provide species-level resolution in all groups, and those that do lack primer sets effective across the phylum, precluding high-throughput processing. This(More)
Determining the host feeding patterns of mosquitoes by identifying the origin of their blood-meals is an important part of understanding the role of vector species in current and future disease transmission cycles. Collecting large numbers of blood-fed mosquitoes from the field is difficult, therefore it is important to maximise the information obtained(More)
Each holotype specimen provides the only objective link to a particular Linnean binomen. Sequence information from them is increasingly valuable due to the growing usage of DNA barcodes in taxonomy. As type specimens are often old, it may only be possible to recover fragmentary sequence information from them. We tested the efficacy of short sequences from(More)
The study analyzes sequence variation of two mitochondrial genes (COI, cytb) in Pediculus humanus from three countries (Egypt, Pakistan, South Africa) that have received little prior attention, and integrates these results with prior data. Analysis indicates a maximum K2P distance of 10.3% among 960 COI sequences and 13.8% among 479 cytb sequences. Three(More)
It is essential that any DNA barcode reference library be based upon correctly identified specimens. The Barcode of Life Data Systems (BOLD) requires information such as images, geo-referencing, and details on the museum holding the voucher specimen for each barcode record to aid recognition of potential misidentifications. Nevertheless, there are(More)