0000000001303374
AUTHOR
Michael A. Miles
Nuclear rDNA ITS-2 sequences reveal polyphyly of Panstrongylus species (Hemiptera: Reduviidae: Triatominae), vectors of Trypanosoma cruzi1
Panstrongylus species are widely distributed throughout the Americas, where they act as vectors of Trypanosoma cruzi, agent of Chagas disease. Their intraspecific relationships, taxonomic position and phylogeny in relation to other Triatomini were explored using ribosomal DNA (rDNA) internal transcribed spacer 2 (ITS-2) sequence polymorphisms and maximum parsimony, distance and maximum likelihood analyses of 10 populations representing six species of the genus (P. megistus, P. geniculatus, P. rufotuberculatus, P. lignarius, P. herreri and P. chinai). At the subspecific level, P. megistus appeared more homogeneous than P. rufotuberculatus and P. geniculatus (both with broader distribution). …
Characterisation of a Cryptosporidium parvum-specific cDNA clone and detection of parasite DNA in mucosal scrapings of infected mice.
A cDNA library was constructed using total RNA extracted from oocysts and sporozoites of the protozoan parasite Cryptosporidium parvum. The expression library was screened with an anti-C. parvum antiserum and a clone, Cp3.4, with a 2043 bp insert, was extracted. Southern blot analysis demonstrated a single copy gene that was located on a 1.6 Mb chromosome. The gene was found to be C. parvum specific as Cp3.4 did not cross-hybridise with chromosomal DNA from three other apicomplexan parasites. The cDNA encodes a polypeptide with a predicted membrane helix at its C-terminal end which is flanked by stretches of acidic amino acids. Overall, the polypeptide has a low isoelectric point (pI) of 3.…
Under pressure: phenotypic divergence and convergence associated with microhabitat adaptations in Triatominae
AbstractBackgroundTriatomine bugs, the vectors of Chagas disease, associate with vertebrate hosts in highly diverse ecotopes. When these blood-sucking bugs adapt to new microhabitats, their phenotypes may change. Although understanding phenotypic variation is key to the study of adaptive evolution and central to phenotype-based taxonomy, the drivers of phenotypic change and diversity in triatomines remain poorly understood.Methods/FindingsWe combined a detailed phenotypic appraisal (including morphology and morphometrics) with mitochondrialcytband nuclear ITS2 DNA-sequence analyses to studyRhodnius ecuadoriensispopulations from across the species’ range. We found three major, naked-eye phen…
Additional file 3 of Under pressure: phenotypic divergence and convergence associated with microhabitat adaptations in Triatominae
Additional file 3: Text S1. Detailed descriptions of the diverse Rhodnius ecuadoriensis phenotypes.
Correction to: Under pressure: phenotypic divergence and convergence associated with microhabitat adaptations in Triatominae.
An amendment to this paper has been published and can be accessed via the original article.
Venezuela's humanitarian crisis, resurgence of vector-borne diseases, and implications for spillover in the region
In the past 5–10 years, Venezuela has faced a severe economic crisis, precipitated by political instability and declining oil revenue. Public health provision has been affected particularly. In this Review, we assess the impact of Venezuela's health-care crisis on vector-borne diseases, and the spillover into neighbouring countries. Between 2000 and 2015, Venezuela witnessed a 359% increase in malaria cases, followed by a 71% increase in 2017 (411 586 cases) compared with 2016 (240 613). Neighbouring countries, such as Brazil, have reported an escalating trend of imported malaria cases from Venezuela, from 1538 in 2014 to 3129 in 2017. In Venezuela, active Chagas disease transmission has be…
Additional file 4 of Under pressure: phenotypic divergence and convergence associated with microhabitat adaptations in Triatominae
Additional file 4: Figure S1. Phenotype–microhabitat–phylogeny correspondences. Multispecies coalescent species tree (as in Fig. 9 of the main text), with pictures (approximately to the same scale) of adult Rhodnius ecuadoriensis and its closest relatives—R. colombiensis, R. pallescens and R. pictipes. The distribution of phenotypes along the phylogeny suggests that the common ancestor of the diverse R. ecuadoriensis forms was most likely a relatively large, straw-like-colored bug. Similarly, the distribution of primary microhabitats suggests that a shift of southern-Andean populations from palm crowns (green stars) to vertebrate nests (orange circles) resulted in convergence towards the sm…
Additional file 7 of Under pressure: phenotypic divergence and convergence associated with microhabitat adaptations in Triatominae
Additional file 7: Alignment S3. Nuclear ITS2 haplotypes in Rhodnius ecuadoriensis from Ecuador and Peru, plus outgroup species (R. colombiensis, R. pallescens and R. pictipes).
Additional file 1 of Under pressure: phenotypic divergence and convergence associated with microhabitat adaptations in Triatominae
Additional file 1: Table S1. Populations, specimen details and haplotype codes of 106 Rhodnius ecuadoriensis bugs used in morphometric and/or molecular analyses. A summary table with the numbers of bugs used in each analysis is also provided.
Additional file 6 of Under pressure: phenotypic divergence and convergence associated with microhabitat adaptations in Triatominae
Additional file 6: Alignment S2. Fourteen nuclear ITS2 haplotypes found in Rhodnius ecuadoriensis from Ecuador and Peru.
Additional file 2 of Under pressure: phenotypic divergence and convergence associated with microhabitat adaptations in Triatominae
Additional file 2: Alignment S1. Mitochondrial cytochrome b haplotypes in Rhodnius ecuadoriensis from Ecuador and Peru, plus outgroup species (R. colombiensis, R. pallescens, R. pictipes).
Additional file 5 of Under pressure: phenotypic divergence and convergence associated with microhabitat adaptations in Triatominae
Additional file 5: Figure S2. Centroid-size comparisons. Population boxplots and Tukey-Kramer (T-K) tests for head and forewing centroid sizes derived from geometric morphometrics.