Phenology of the diamondback moth (Plutella xylostella) in the UK and provision of decision support for Brassica growers
Wainwright C, Jenkins S, Wilson D, Elliott M, Jukes A, Collier R
In the UK, severe infestations by Plutella xylostella occur sporadically and are due mainly to the immigration of moths. The aim of this study was to develop a more detailed understanding of the phenology of P. xylostella in the UK and investigate methods of monitoring moth activity, with the aim of providing warnings to growers. The summarised sightings by citizen scientists on a web page were accessed regularly by growers and, at present, this approach appears to be the most effective way of providing timely warnings.
Diversity of HLA Class I and Class II blocks and conserved extended haplotypes in Lacandon Mayans
Barquera R, Zuniga J, Flores-Riveras J, Corona T, Penman BS, Hernandez-Zaragoza DI, Soler M, Jonapa-Gomez L, Mallempati KC, Yescas P, Ochoa-Morales A, Barsakis K, Aguilar-Vasquez JA, Garcia-Lechuga M, Mindrinos M, Yunis M, Jimenez-Alvarez L, Mena-Henandez L, Ortega E, Cruz-Laguans A, Tovar-Mendez VH, Granados J, Fernandez-Vina M, Yunis E
Here we studied HLA blocks and haplotypes in a group of 218 Lacandon Maya Native American using a high-resolution next generation sequencing (NGS) method. We assessed the genetic diversity of HLA class I and class II in this population, and determined the most probable ancestry of Lacandon Maya HLA class I and class II haplotypes.. We found the expected negative relationship between genetic diversity and distance from Africa in the global dataset, but no relationship between HLA genetic diversity and distance from Africa when Native American populations were considered alone.
Vaccination Against Canine Leishmaniasis in Brazil: A Position Paper
Filipe Dantas-Torres et al including Orin Courtenay
Prevention of canine Leishmania infantum infection is critical to management of visceral leishmaniasis in people living in endemic areas of Brazil. A bill currently under consideration, proposes to establish a national vaccination policy against canine leishmaniasis in Brazil. However, there is no solid scientific evidence supporting the idea that this could reduce transmission from infected vaccinated dogs to sand flies to a level that would significantly reduce the risk of L. infantum infection or visceral leishmaniasis in humans. Thus, we advocate that insecticide-impregnated collars should be made mandatory for public health purposes and that vaccines are applied on a case-by-case, optional basis for individual dog protection.
IGS region polymorphisms are responsible for failure of commonly used species-specific primers in Fusarium proliferatum isolates from diseased garlic
Laura Gálvez, John P. Clarkson and Daniel Palmero
Fusarium proliferatum is a globally distributed fungal pathogen that affects a range of crop hosts and is one of the main producers of mycotoxins in foods such as fumonisins. Specific PCR primers are commonly used for detection and identification of this pathogen. The aim of this study was to validate previously published F. proliferatum‐specific primers targeting the IGS region and characterise intraspecific variation and homologous recombination events for isolates obtained from diseased garlic bulbs in Spain. Our results suggest that the IGS region may be too variable as a reliable target for F. proliferatum‐specific identification.
Xavier Didelot publications
Identification of hidden population structure in time-scaled phylogenies
Volz EM, Wiuf C, Grad YH, Frost SDW, Dennis AM, Didelot X
Population structure influences genealogical patterns, however data pertaining to how populations are structured are often unavailable or not directly observable. Inference of population structure is highly important in molecular epidemiology where pathogen phylogenetics is increasingly used to infer transmission patterns and detect outbreaks. Discrepancies between observed and idealised genealogies can be quantified, and where significant differences occur, may reveal the action of natural selection, host population structure, or other demographic and epidemiological heterogeneities. We have developed a fast non-parametric statistical test for detection of cryptic population structure in time-scaled phylogenetic trees and find that population structure detected using these methods closely overlaps with the appearance and expansion of mutations conferring antimicrobial resistance.
Genomic epidemiology of Vibrio cholerae reveals the regional and global spread of two epidemic non-toxigenic lineages
Wang H, Yang C, Sun Z, Zheng W, Zhang W, Yu H, Wu Y, Didelot X, Yang R, Pan J, Cui Y
Non-toxigenic Vibrio cholerae isolates have been found associated with diarrheal disease globally, however, the global picture of non-toxigenic infections is largely unknown. Among non-toxigenic V. cholerae, ctxAB negative, tcpA positive (CNTP) isolates have the highest risk of disease. From 2001 to 2012, 71 infectious diarrhea cases were reported in Hangzhou, China, caused by CNTP serogroup O1 isolates. We sequenced 119 V. cholerae genomes isolated from patients, carriers and the environment in Hangzhou, and compared them with global isolates. We fill the missing links in the global spread of the two non-toxigenic serogroup O1 V. cholerae lineages that can cause human infection. The results are important for the design of future disease control strategies.
Low temperature stimulates spatial molecular reprogramming of the Arabidopsis seed germination programme
Jack Mitchell, Nur K Mukhtar and George W Bassel
The timing of the germination of seeds is highly responsive to inputs from the environment. Temperature plays a key role in the control of germination, with low temperatures acting to stimulate this developmental transition in many species. In Arabidopsis, extensive gene expression changes have been reported at the whole seed level in response to cold, while much less is known about their spatial distribution across the diverse cell types of the embryo. In this study we showed that the vasculature plays a role in the low temperature-mediated stimulation of germination in this species, while novel cell types are recruited to promote germination in response to stratification.