• 3D virtual histology at the host/parasite interface: visualisation of the master manipulator, Dicrocoelium dendriticum, in the brain of its ant host

      Martin-Vega, D; Garbout, A; Ahmed, F; Wicklein, M; Goater, CP; Colwell, DD; Hall, MJR (Springer Science and Business Media LLC, 2018-06-05)
      Some parasites are able to manipulate the behaviour of their hosts to their own advantage. One of the most well-established textbook examples of host manipulation is that of the trematode Dicrocoelium dendriticum on ants, its second intermediate host. Infected ants harbour encysted metacercariae in the gaster and a non-encysted metacercaria in the suboesophageal ganglion (SOG); however, the mechanisms that D. dendriticum uses to manipulate the ant behaviour remain unknown, partly because of a lack of a proper and direct visualisation of the physical interface between the parasite and the ant brain tissue. Here we provide new insights into the potential mechanisms that this iconic manipulator uses to alter its host’s behaviour by characterising the interface between D. dendriticum and the ant tissues with the use of non-invasive micro-CT scanning. For the first time, we show that there is a physical contact between the parasite and the ant brain tissue at the anteriormost part of the SOG, including in a case of multiple brain infection where only the parasite lodged in the most anterior part of the SOG was in contact with the ant brain tissue. We demonstrate the potential of micro-CT to further understand other parasite/host systems in parasitological research.
    • Analyses of mitochondrial amino acid sequence datasets support the proposal that specimens of Hypodontus macropi from three species of macropodid hosts represent distinct species

      Jabbar, A; Beveridge, I; Mohandas, N; Chilton, NB; Littlewood, T; Jex, AR; Gasser, RB (Springer Science and Business Media LLC, 2013-11-21)
      Background: Hypodontus macropi is a common intestinal nematode of a range of kangaroos and wallabies (macropodid marsupials). Based on previous multilocus enzyme electrophoresis (MEE) and nuclear ribosomal DNA sequence data sets, H. macropi has been proposed to be complex of species. To test this proposal using independent molecular data, we sequenced the whole mitochondrial (mt) genomes of individuals of H. macropi from three different species of hosts (Macropus robustus robustus, Thylogale billardierii and Macropus [Wallabia] bicolor) as well as that of Macropicola ocydromi (a related nematode), and undertook a comparative analysis of the amino acid sequence datasets derived from these genomes. Results: The mt genomes sequenced by next-generation (454) technology from H. macropi from the three host species varied from 13,634 bp to 13,699 bp in size. Pairwise comparisons of the amino acid sequences predicted from these three mt genomes revealed differences of 5.8% to 18%. Phylogenetic analysis of the amino acid sequence data sets using Bayesian Inference (BI) showed that H. macropi from the three different host species formed distinct, well-supported clades. In addition, sliding window analysis of the mt genomes defined variable regions for future population genetic studies of H. macropi in different macropodid hosts and geographical regions around Australia. Conclusions: The present analyses of inferred mt protein sequence datasets clearly supported the hypothesis that H. macropi from M. robustus robustus, M. bicolor and T. billardierii represent distinct species.
    • Ancient mitogenomics clarifies radiation of extinct Mascarene giant tortoises (Cylindraspis spp.)

      Kehlmaier, C; Graciá, E; Campbell, P; Hofmeyr, MD; SCHWEIGER, S; Martínez-Silvestre, A; Joyce, W; Fritz, U (Springer Science and Business Media LLC, 2019-11-25)
      The five extinct giant tortoises of the genus Cylindraspis belong to the most iconic species of the enigmatic fauna of the Mascarene Islands that went largely extinct after the discovery of the islands. To resolve the phylogeny and biogeography of Cylindraspis, we analysed a data set of 45 mitogenomes that includes all lineages of extant tortoises and eight near-complete sequences of all Mascarene species extracted from historic and subfossil material. Cylindraspis is an ancient lineage that diverged as early as the late Eocene. Diversification of Cylindraspis commenced in the mid-Oligocene, long before the formation of the Mascarene Islands. This rejects any notion suggesting that the group either arrived from nearby or distant continents over the course of the last millions of years or had even been translocated to the islands by humans. Instead, Cylindraspis likely originated on now submerged islands of the Réunion Hotspot and utilized these to island hop to reach the Mascarenes. The final diversification took place both before and after the arrival on the Mascarenes. With Cylindraspis a deeply divergent clade of tortoises became extinct that evolved long before the dodo or the Rodrigues solitaire, two other charismatic species of the lost Mascarene fauna.
    • Assessing gaps in reporting non-target mortality in island rodent eradication operations

      Ward, S; Fournier, AMV; Bond, AL (Springer Science and Business Media LLC, 2019-06-25)
      Eradicating invasive species is a key part of island restoration, and can reverse the devastating impacts on native biota. Rodents are one of the most widespread invasive species, found on 80% of oceanic island systems, but have been removed from hundreds of islands through the application of anticoagulant-treated cereal bait. While such eradication operations are often net positive events for island ecosystems over the long-term, some native biota are also susceptible, resulting in short-term non-target mortality. One of the most widely distributed groups of birds, rails and allies (Rallidae) are highly adaptable, often endemic, and are known often to suffer mortality during rodent eradication operations, to varying degrees. Our goal was determine if the year of eradication or the size of the island predicted whether non-target mortalities were reported, including those that were true absences of mortality. We examined 122 eradication operations on 81 islands with rails present from 1983 to 2015, and found 78% with no reported information on non-target mortality using our search criteria. We found non-target mortality reporting has decreased over time, and there was no relationship with island size. Post-operational monitoring of eradication operations should thoroughly record non-target mortality to improve our understanding of factors affecting non-target mortality, and the efficacy of mitigation measures.
    • Assessment of the genetic relationship between Dictyocaulus species from Bos taurus and Cervus elaphus using complete mitochondrial genomic datasets

      Gasser, RB; Jabbar, A; Mohandas, N; Höglund, J; Hall, RS; Littlewood, T; Jex, AR (Springer Science and Business Media LLC, 2012-10-30)
      Background: Dictyocaulus species are strongylid nematodes of major veterinary significance in ruminants, such as cattle and cervids, and cause serious bronchitis or pneumonia (dictyocaulosis or “husk”). There has been ongoing controversy surrounding the validity of some Dictyocaulus species and their host specificity. Here, we sequenced and characterized the mitochondrial (mt) genomes of Dictyocaulus viviparus (from Bos taurus) with Dictyocaulus sp. cf. eckerti from red deer (Cervus elaphus), used mt datasets to assess the genetic relationship between these and related parasites, and predicted markers for future population genetic or molecular epidemiological studies. Methods: The mt genomes were amplified from single adult males of D. viviparus and Dictyocaulus sp. cf. eckerti (from red deer) by long-PCR, sequenced using 454-technology and annotated using bioinformatic tools. Amino acid sequences inferred from individual genes of each of the two mt genomes were compared, concatenated and subjected to phylogenetic analysis using Bayesian inference (BI), also employing data for other strongylids for comparative purposes. Results: The circular mt genomes were 13,310 bp (D. viviparus) and 13,296 bp (Dictyocaulus sp. cf. eckerti) in size, and each contained 12 protein-encoding, 22 transfer RNA and 2 ribosomal RNA genes, consistent with other strongylid nematodes sequenced to date. Sliding window analysis identified genes with high or low levels of nucleotide diversity between the mt genomes. At the predicted mt proteomic level, there was an overall sequence difference of 34.5% between D. viviparus and Dictyocaulus sp. cf. eckerti, and amino acid sequence variation within each species was usually much lower than differences between species. Phylogenetic analysis of the concatenated amino acid sequence data for all 12 mt proteins showed that both D. viviparus and Dictyocaulus sp. cf. eckerti were closely related, and grouped to the exclusion of selected members of the superfamilies Metastrongyloidea, Trichostrongyloidea, Ancylostomatoidea and Strongyloidea. Conclusions: Consistent with previous findings for nuclear ribosomal DNA sequence data, the present analyses indicate that Dictyocaulus sp. cf. eckerti (red deer) and D. viviparus are separate species. Barcodes in the two mt genomes and proteomes should serve as markers for future studies of the population genetics and/or epidemiology of these and related species of Dictyocaulus.
    • Changes to publication requirements made at the XVIII International Botanical Congress in Melbourne - what does e-publication mean for you?

      Knapp, S; McNeill, J; Turland, NJ (Springer Science and Business Media LLC, 2011-09-14)
      Changes to the International Code of Botanical Nomenclature are decided on every 6 years at Nomenclature Sections associated with International Botanical Congresses (IBC). The XVIII IBC was held in Melbourne, Australia; the Nomenclature Section met on 18-22 July 2011 and its decisions were accepted by the Congress at its plenary session on 30 July. Several important changes were made to the Code as a result of this meeting that will affect publication of new names. Two of these changes will come into effect on 1 January 2012, some months before the Melbourne Code is published. Electronic material published online in Portable Document Format (PDF) with an International Standard Serial Number (ISSN) or an International Standard Book Number (ISBN) will constitute effective publication, and the requirement for a Latin description or diagnosis for names of new taxa will be changed to a requirement for a description or diagnosis in either Latin or English. In addition, effective from 1 January 2013, new names of organisms treated as fungi must, in order to be validly published, include in the protologue (everything associated with a name at its valid publication) the citation of an identifier issued by a recognized repository (such as MycoBank). Draft text of the new articles dealing with electronic publication is provided and best practice is outlined.
    • Chromoblastomycosis after a leech bite complicated by myiasis: a case report

      Slesak, G; Inthalad, S; Strobel, M; Marschal, M; Hall, MJR; Newton, PN (Springer Science and Business Media LLC, 2011-01-12)
      Background Chromoblastomycosis is a chronic mycotic infection, most common in the tropics and subtropics, following traumatic fungal implantation. Case presentation A 72 year-old farmer was admitted to Luang Namtha Provincial Hospital, northern Laos, with a growth on the left lower leg which began 1 week after a forefoot leech bite 10 years previously. He presented with a cauliflower-like mass and plaque-like lesions on his lower leg/foot and cellulitis with a purulent tender swelling of his left heel. Twenty-two Chrysomya bezziana larvae were extracted from his heel. PCR of a biopsy of a left lower leg nodule demonstrated Fonsecaea pedrosoi, monophora, or F. nubica. He was successfully treated with long term terbinafin plus itraconazole pulse-therapy and local debridement. Conclusions Chromoblastomycosis is reported for the first time from Laos. It carries the danger of bacterial and myiasis superinfection. Leech bites may facilitate infection.
    • Confocal laser scanning microscopy as a valuable tool in Diptera larval morphology studies

      Grzywacz, A; Góral, T; Szpila, K; Hall, MJR (Springer Science and Business Media LLC, 2014-09-19)
      Larval morphology of flies is traditionally studied using light microscopy, yet in the case of fine structures compound light microscopy is limited due to problems of resolution, illumination and depth of field, not allowing for precise recognition of sclerites’ edges and interactions. Using larval instars of cyclorrhaphan Diptera, we show the usefulness of confocal laser scanning microscopy (CLSM) for studying the morphological characters of immature stages by taking advantage of the autofluorescent properties of cephaloskeleton structures. We compare data obtained from killed but unprepared larvae with those from larvae prepared by clearing according to two commonly used methods, either with potassium hydroxide or with Hoyer’s medium. We also evaluated the CLSM application for examining already slide-mounted larvae stored in museum collections and those freshly prepared. Our results indicate that CLSM and 3D reconstruction are excellent for visualizing small, compound structures of cylrorrhaphan larvae cephaloskeleton, if appropriate clearing techniques, i.e. the application of KOH, are used. Maximum intensity projection of confocal data sets obtained from material freshly prepared and that stored in museum collection does not differ. Because of this and the fact that KOH is commonly used as a clearing method to examine the cephaloskeleton of Diptera larvae, it is possible, and highly recommended, to use slides already prepared with this method for re-examination by CLSM. We conclude that CLSM application can be an invaluable source of data for studies of larval morphology of Cyclorrhapha by way of taxonomic diagnoses, character identification and improvement in characters homologization.
    • Convergent evolution in toothed whale cochleae

      Park, Travis; Mennecart, B; Costeur, L; Grohé, C; Cooper, N (Springer Science and Business Media LLC, 2019-10-24)
      Background Odontocetes (toothed whales) are the most species-rich marine mammal lineage. The catalyst for their evolutionary success is echolocation - a form of biological sonar that uses high-frequency sound, produced in the forehead and ultimately detected by the cochlea. The ubiquity of echolocation in odontocetes across a wide range of physical and acoustic environments suggests that convergent evolution of cochlear shape is likely to have occurred. To test this, we used SURFACE; a method that fits Ornstein-Uhlenbeck (OU) models with stepwise AIC (Akaike Information Criterion) to identify convergent regimes on the odontocete phylogeny, and then tested whether convergence in these regimes was significantly greater than expected by chance. Results We identified three convergent regimes: (1) True’s (Mesoplodon mirus) and Cuvier’s (Ziphius cavirostris) beaked whales; (2) sperm whales (Physeter macrocephalus) and all other beaked whales sampled; and (3) pygmy (Kogia breviceps) and dwarf (Kogia sima) sperm whales and Dall’s porpoise (Phocoenoides dalli). Interestingly the ‘river dolphins’, a group notorious for their convergent morphologies and riverine ecologies, do not have convergent cochlear shapes. The first two regimes were significantly convergent, with habitat type and dive type significantly correlated with membership of the sperm whale + beaked whale regime. Conclusions The extreme acoustic environment of the deep ocean likely constrains cochlear shape, causing the cochlear morphology of sperm and beaked whales to converge. This study adds support for cochlear morphology being used to predict the ecology of extinct cetaceans.
    • Decomposed liver has a significantly adverse affect on the development rate of the blowfly Calliphora vicina

      Richards, CS; Rowlinson, CC; Cuttiford, Lue; Grimsley, R; Hall, MJR (Springer Science and Business Media LLC, 2012-04-26)
      The development rate of immature Calliphora vicina reared on decomposed liver was significantly slower, by as much as 30 h (55.4 % of total development time) for mid-sized larvae, and 71 h (35.0 %) and 58 h (14.6 %) if using times to the onset of pupariation and eclosion, respectively, than those of immatures that developed on fresh whole pig's liver. Development rates of larvae reared on decomposed liver were also slower than those of larvae reared on minced pig's liver and frozen/thawed pig's liver. These results suggest that any estimate of minimum post-mortem interval may result in an over estimate if the blowflies used were developing on an already decomposed body.
    • Detection of ascaridoid nematode parasites in the important marine food-fish Conger myriaster (Brevoort) (Anguilliformes: Congridae) from the Zhoushan Fishery, China

      Chen, H-X; Zhang, L-P; Gibson, David I.; Lü, L; Xu, Z; Li, H-T; Ju, H-D; Li, L (Springer Science and Business Media LLC, 2018-05-02)
      Background The whitespotted conger Conger myriaster (Brevoort) (Anguilliformes: Congridae) is an extremely marketable food fish, commonly consumed as sashimi or sushi in some Asian countries (i.e. Japan, Korea and China). Conger myriaster is also suspected as being an extremely important source of human anisakidosis. However, there is currently very little information on the levels of infection with ascaridoid nematode parasites in this economically important marine fish. The aims of the present study are to determine the species composition, prevalence and mean intensity of ascaridoid parasites of C. myriaster caught in the Zhoushan Fishery. Results A total of 1142 third-stage ascaridoid larvae were isolated from 204 C. myriaster. The overall prevalence of infection was 100% (mean intensity 5.6). Nine species of such larvae were accurately identified using integrative taxonomic techniques involving both morphological and genetic data; these included Anisakis pegreffii, A. typica and A. simplex (sensu stricto) × A. pegreffii, Hysterothylacium fabri, H. aduncum, H. sinense, H. amoyense, H. zhoushanense and Raphidascaris lophii. Although high levels of infection and species richness were revealed in C. myriaster, most of the ascaridoid parasites (1135 individuals) were collected from the body cavity and visceral organs of the fish and only seven individuals of A. pegreffii were found in the musculature. Conclusions This study represents the first report C. myriaster from the Zhoushan Fishery being heavily infected with third-stage ascaridoid larvae. Among the ascaridoid larvae parasitic in this fish, an important etiological agent of human anisakidosis, A. pegreffii (L3), represents the predominant species. The genus Hysterothylacium has the highest species richness, with H. fabri (L3) being the most prevalent species. This high level of infection of A. pegreffii (L3) in C. myriaster suggests a high risk of anisakidosis or associated allergies for people consuming raw or poorly cooked fish originating from this marine area. These findings provide important basic information on the occurrence and infection parameters of ascaridoid nematodes in this economically important marine fish. They also have significant implications for the prevention and control of human anisakidosis when conger eels from the Zhoushan Fishery are consumed.
    • Effects of storage temperature on the change in size of Calliphora vicina larvae during preservation in 80% ethanol

      Richards, CS; Rowlinson, CC; Hall, MJR (Springer Science and Business Media LLC, 2012-03-08)
      The size of immature blowflies is a common measure to estimate the minimum time between death and the discovery of a corpse, also known as the minimum post-mortem interval. This paper investigates the effects of preservation, in 80% ethanol, on the length and weight of first instar, second instar, feeding third instar, and post-feeding third instar Calliphora vicina larvae, at three different storage temperatures. For each larval stage, the length of larvae was recorded after 0 h, 3 h, 6 h, 9 h, 12 h, 24 h, 72 h, 7 days, 14 days, 30 days, 91 days, 182 days, 273 days, and 365 days of storage in 80% ethanol, at −25°C, 6°C and 24°C. Storage temperature had no statistically significant effect on the change in larval length and weight for all larval stages, but larval length and weight were significantly affected by the duration of preservation for first, second, and feeding third instar larvae, but not for post-feeding larvae. Generally, first and second instar larvae reduced in size over time, while feeding third instar larvae increased slightly in size, and post-feeding larvae did not change in size over time. The length of blowfly larvae preserved in 80% ethanol is not affected by constant storage temperatures between −25°C and +24°C, but we recommend that forensic entomologists should use the models provided to correct for changes in larval length that do become apparent over time.
    • The increased sensitivity of qPCR in comparison to Kato-Katz is required for the accurate assessment of the prevalence of soil-transmitted helminth infection in settings that have received multiple rounds of mass drug administration

      Dunn, JC; PAPAIAKOVOU, MARINA; Han, KT; Chooneea, D; Bettis, AA; Wyine, NY; Lwin, AMM; Maung, NS; Misra, Raju; Littlewood, T; et al. (Springer Science and Business Media LLC, 2020-06-24)
      Background The most commonly used diagnostic tool for soil-transmitted helminths (STH) is the Kato-Katz (KK) thick smear technique. However, numerous studies have suggested that the sensitivity of KK can be problematic, especially in low prevalence and low intensity settings. An emerging alternative is quantitative polymerase chain reaction (qPCR). Methods In this study, both KK and qPCR were conducted on stool samples from 648 participants in an STH epidemiology study conducted in the delta region of Myanmar in June 2016. Results Prevalence of any STH was 20.68% by KK and 45.06% by qPCR. Prevalence of each individual STH was also higher by qPCR than KK, the biggest difference was for hookworm with an approximately 4-fold increase between the two diagnostic techniques. Prevalence of Ancylostoma ceylanicum, a parasite predominately found in dogs, was 4.63%, indicating that there is the possibility of zoonotic transmission in the study setting. In individuals with moderate to high intensity infections there is evidence for a linear relationship between eggs per gram (EPG) of faeces, derived from KK, and DNA copy number, derived from qPCR which is particularly strong for Ascaris lumbricoides. Conclusions The use of qPCR in low prevalence settings is important to accurately assess the epidemiological situation and plan control strategies for the ‘end game’. However, more work is required to accurately assess STH intensity from qPCR results and to reduce the cost of qPCR so that is widely accessible in STH endemic countries.
    • The mitochondrial genomes of Ancylostoma caninum and Bunostomum phlebotomum – two hookworms of animal health and zoonotic importance

      Jex, AR; Waeschenbach, A; Hu, M; van Wyk, JA; Beveridge, I; Littlewood, T; Gasser, RB (Springer Science and Business Media LLC, 2009-02-11)
      Background: Hookworms are blood-feeding nematodes that parasitize the small intestines of many mammals, including humans and cattle. These nematodes are of major socioeconomic importance and cause disease, mainly as a consequence of anaemia (particularly in children or young animals), resulting in impaired development and sometimes deaths. Studying genetic variability within and among hookworm populations is central to addressing epidemiological and ecological questions, thus assisting in the control of hookworm disease. Mitochondrial (mt) genes are known to provide useful population markers for hookworms, but mt genome sequence data are scant. Results: The present study characterizes the complete mt genomes of two species of hookworm, Ancylostoma caninum (from dogs) and Bunostomum phlebotomum (from cattle), each sequenced (by 454 technology or primer-walking), following long-PCR amplification from genomic DNA (~20–40 ng) isolated from individual adult worms. These mt genomes were 13717 bp and 13790 bp in size, respectively, and each contained 12 protein coding, 22 transfer RNA and 2 ribosomal RNA genes, typical for other secernentean nematodes. In addition, phylogenetic analysis (by Bayesian inference and maximum likelihood) of concatenated mt protein sequence data sets for 12 nematodes (including Ancylostoma caninum and Bunostomum phlebotomum), representing the Ascaridida, Spirurida and Strongylida, was conducted. The analysis yielded maximum statistical support for the formation of monophyletic clades for each recognized nematode order assessed, except for the Rhabditida. Conclusion: The mt genomes characterized herein represent a rich source of population genetic markers for epidemiological and ecological studies. The strong statistical support for the construction of phylogenetic clades and consistency between the two different tree-building methods employed indicate the value of using whole mt genome data sets for systematic studies of nematodes. The grouping of the Spirurida and Ascaridida to the exclusion of the Strongylida was not supported in the present analysis, a finding which conflicts with the current evolutionary hypothesis for the Nematoda based on nuclear ribosomal gene data.
    • Molecular circumscription of new species of Gyrocotyle Diesing, 1850 (Cestoda) from deep-sea chimaeriform holocephalans in the North Atlantic

      Bray, RA; Waeschenbach, A; Littlewood, T; Halvorsen, O; Olson, PD (Springer Science and Business Media LLC, 2020-04-23)
      Chimaeras, or ratfishes, are the only extant group of holocephalan fishes and are the sole host group of gyrocotylidean cestodes, which represent a sister group of the true tapeworms (Eucestoda). These unique, non-segmented cestodes have been known since the 1850s and multiple species and genera have been erected despite a general agreement that the delineation of species on the basis of morphology is effectively impossible. Thus, in the absence of molecular studies, the validity of gyrocotylid taxa and their specific host associations has remained highly speculative. Here we report the presence of Gyrocotyle spp. from rarely-caught deep-sea chimaeras collected in the North-East Atlantic, and describe two new species: G. haffii n. sp. from the bent-nose chimaera, Harriota raleighana Goode & Bean, and G. discoveryi n. sp. from the large-eyed rabbit fish, Hydrolagus mirabilis (Collett). Nuclear ribosomal sequence data were generated for individual parasites taken from different host species collected on different dates and from different localities and were combined with previously published sequences. Phylogenetic analyses supported the recognition of independent lineages and clusters, indicative of species, but were indecisive in recovering the root of the tree in analyses that included non-gyrocotylid outgroup taxa. The molecular data reveal variation not reflected in morphology and point to a complex picture of genetic divergence shaped by both isolation and migration in the deep-sea environment.
    • Morphology of the first instar larva of obligatory traumatic myiasis agents (Diptera: Calliphoridae, Sarcophagidae)

      Szpila, K; Hall, MJR; Wardhana, AH; Pape, T (Springer Science and Business Media LLC, 2014-02-20)
      There are only three fly species that are obligate agents of traumatic myiasis of humans and livestock: a single species of flesh fly, Wohlfahrtia magnifica (Sarcophagidae), and two species of blow flies, Chrysomya bezziana and Cochliomyia hominivorax (Calliphoridae). The morphology of their first instar larvae is thoroughly and consistently documented here with light microscopy photographs and scanning electron microscopy micrographs. The following morphological structures are documented: pseudocephalon, antennal complex, maxillary palpus, oral ridges, thoracic and abdominal spinulation, spiracular field, posterior spiracles and cephaloskeleton. New diagnostic features drawn from the cephaloskeleton and the spinulation of abdominal segments, including the anal pad, are discovered and extensively described. Earlier descriptions in the literature are revisited, and major discrepancies between these and the results of the current study are discussed. The present results allow clarification, correction and, especially, complementation of information provided by earlier authors. The relatively distant taxonomic position of all three species is evidence that obligatory myiasis has arisen independently, and the extensively similar morphology in the first instar larvae of Chrysomya bezziana, Cochliomyia hominivorax and W. magnifica in comparison to necrophagous species, especially the enhancement of the anterior part of the cephaloskeleton and the segmental spinulation, is therefore best interpreted as homoplasic adaptations to a life strategy as obligate vertebrate parasites. An identification key for first instar larvae of all obligatory traumatic myiasis agents of mammals is provided.
    • The phylogenetic position of Acoela as revealed by the complete mitochondrial genome of Symsagittifera roscoffensis

      Mwinyi, A; Bailly, X; Bourlat, SJ; Jondelius, U; Littlewood, T; Podsiadlowski, L (Springer Science and Business Media LLC, 2010-10-13)
      Background Acoels are simply organized unsegmented worms, lacking hindgut and anus. Several publications over recent years challenge the long-held view that acoels are early offshoots of the flatworms. Instead a basal position as sister group to all other bilaterian animals was suggested, mainly based on molecular evidence. This led to the view that features of acoels might reflect those of the last common ancestor of Bilateria, and resulted in several evo-devo studies trying to interpret bilaterian evolution using acoels as a proxy model for the "Urbilateria". Results We describe the first complete mitochondrial genome sequence of a member of the Acoela, Symsagittifera roscoffensis. Gene content and circular organization of the mitochondrial genome does not significantly differ from other bilaterian animals. However, gene order shows no similarity to any other mitochondrial genome within the Metazoa. Phylogenetic analyses of concatenated alignments of amino acid sequences from protein coding genes support a position of Acoela and Nemertodermatida as the sister group to all other Bilateria. Our data provided no support for a sister group relationship between Xenoturbellida and Acoela or Acoelomorpha. The phylogenetic position of Xenoturbella bocki as sister group to or part of the deuterostomes was also unstable. Conclusions Our phylogenetic analysis supports the view that acoels and nemertodermatids are the earliest divergent extant lineage of Bilateria. As such they remain a valid source for seeking primitive characters present in the last common ancestor of Bilateria. Gene order of mitochondrial genomes seems to be very variable among Acoela and Nemertodermatida and the groundplan for the metazoan mitochondrial genome remains elusive. More data are needed to interpret mitochondrial genome evolution at the base of Bilateria.
    • Pigs vs people: the use of pigs as analogues for humans in forensic entomology and taphonomy research

      Matuszewski, S; Hall, MJR; Moreau, G; Schoenly, KG; Tarone, AM; Villet, MH (Springer Science and Business Media LLC, 2019-06-17)
      Most studies of decomposition in forensic entomology and taphonomy have used non-human cadavers. Following the recommendation of using domestic pig cadavers as analogues for humans in forensic entomology in the 1980s, pigs became the most frequently used model cadavers in forensic sciences. They have shaped our understanding of how large vertebrate cadavers decompose in, for example, various environments, seasons and after various ante- or postmortem cadaver modifications. They have also been used to demonstrate the feasibility of several new or well-established forensic techniques. The advent of outdoor human taphonomy facilities enabled experimental comparisons of decomposition between pig and human cadavers. Recent comparisons challenged the pig-as-analogue claim in entomology and taphonomy research. In this review, we discuss in a broad methodological context the advantages and disadvantages of pig and human cadavers for forensic research and rebut the critique of pigs as analogues for humans. We conclude that experiments using human cadaver analogues (i.e. pig carcasses) are easier to replicate and more practical for controlling confounding factors than studies based solely on humans and, therefore, are likely to remain our primary epistemic source of forensic knowledge for the immediate future. We supplement these considerations with new guidelines for model cadaver choice in forensic science research.
    • Pooling as a strategy for the timely diagnosis of soil-transmitted helminths in stool: value and reproducibility

      PAPAIAKOVOU, MARINA; Wright, J; Pilotte, N; Chooneea, D; Schär, F; Truscott, JE; Dunn, JC; Gardiner, I; Walson, JL; Williams, SA; et al. (Springer Science and Business Media LLC, 2019-09-16)
      Background The strategy of pooling stool specimens has been extensively used in the field of parasitology in order to facilitate the screening of large numbers of samples whilst minimizing the prohibitive cost of single sample analysis. The aim of this study was to develop a standardized reproducible pooling protocol for stool samples, validated between two different laboratories, without jeopardizing the sensitivity of the quantitative polymerase chain reaction (qPCR) assays employed for the detection of soil-transmitted helminths (STHs). Two distinct experimental phases were recruited. First, the sensitivity and specificity of the established protocol was assessed by real-time PCR for each one of the STHs. Secondly, agreement and reproducibility of the protocol between the two different laboratories were tested. The need for multiple stool sampling to avoid false negative results was also assessed. Finally, a cost exercise was conducted which included labour cost in low- and high-wage settings, consumable cost, prevalence of a single STH species, and a simple distribution pattern of the positive samples in pools to estimate time and money savings suggested by the strategy. Results The sensitivity of the pooling method was variable among the STH species but consistent between the two laboratories. Estimates of specificity indicate a ‘pooling approach’ can yield a low frequency of ‘missed’ infections. There were no significant differences regarding the execution of the protocol and the subsequent STH detection between the two laboratories, which suggests in most cases the protocol is reproducible by adequately trained staff. Finally, given the high degree of agreement, there appears to be little or no need for multiple sampling of either individuals or pools. Conclusions Our results suggest that the pooling protocol developed herein is a robust and efficient strategy for the detection of STHs in ‘pools-of-five’. There is notable complexity of the pool preparation to ensure even distribution of helminth DNA throughout. Therefore, at a given setting, cost of labour among other logistical and epidemiological factors, is the more concerning and determining factor when choosing pooling strategies, rather than losing sensitivity and/or specificity of the molecular assay or the method.
    • Relationships between mercury burden, sex, and sexually selected feather ornaments in crested auklet (Aethia cristatella)

      Bond, AL; Jones, IL (Springer Science and Business Media LLC, 2020-03-04)
      Individuals with higher contaminant burdens are expected to be in poorer physical health and be of lower individual body condition and energetic status, potentially resulting in reduced ornamentation or increased asymmetry in bilateral features. The degree and magnitude of this effect also would be expected to vary by sex, as female birds depurate contaminants into eggs. We tested for relationships among mercury in feathers, sex, and elaborate feather ornaments that relate to individual quality in crested auklets (Aethia cristatella), small planktivorous seabirds in the North Pacific Ocean. We found no relationships between mercury and the size of individuals’ forehead crest or degree of measurement asymmetry in auricular plumes, both of which are favoured by intersexual selection. Females had significantly greater mercury concentrations than males (females. 1.02 ± 0.39 μg/g; males, 0.75 ± 0.32 μg/g); but concentrations were below that known to have physiological effects, as expected for a secondary consumer. Sex differences in overwintering area for this long-distance migrant species (more females in the Kuroshio Current Large Marine Ecosystem than males) could be the reason for this seemingly counterintuitive result between sexes. Further research relating mercury burden to overwintering ecology and diet contents would build on our results and further elucidate interrelationships between sex, sexually selected feather ornaments and contaminant burden.