Michael J. Jowers
University of Porto
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Featured researches published by Michael J. Jowers.
Parasites & Vectors | 2016
Samer Angelone-Alasaad; Michael J. Jowers; R. Panadero; Ana Pérez-Creo; Gerardo Pajares; P. Díez-Baños; Ramón C. Soriguer; P. Morrondo
BackgroundFilarioid nematode parasites are major health hazards with important medical, veterinary and economic implications. Recently, they have been considered as indicators of climate change.FindingsIn this paper, we report the first record of Setaria tundra in roe deer from the Iberian Peninsula. Adult S. tundra were collected from the peritoneal cavity during the post-mortem examination of a 2xa0year-old male roe deer, which belonged to a private fenced estate in La Alcarria (Guadalajara, Spain). Since 2012, the area has suffered a high roe deer decline rate (75xa0%), for unknown reasons. Aiming to support the morphological identification and to determine the phylogenetic position of S. tundra recovered from the roe deer, a fragment of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene from the two morphologically identified parasites was amplified, sequenced and compared with corresponding sequences of other filarioid nematode species. Phylogenetic analyses revealed that the isolate of S. tundra recovered was basal to all other formely reported Setaria tundra sequences. The presence of all other haplotypes in Northern Europe may be indicative of a South to North outbreak in Europe.ConclusionsThis is the first report of S. tundra in roe deer from the Iberian Peninsula, with interesting phylogenetic results, which may have further implications in the epidemiological and genetic studies of these filarioid parasites. More studies are needed to explore the reasons and dynamics behind the rapid host/geographic expansion of the filarioid parasites in Europe.
PLOS ONE | 2016
John C. Murphy; Michael J. Jowers; Richard M. Lehtinen; Stevland P. Charles; Guarino R. Colli; Ayrton K. Peres; Catriona R. Hendry; R. Alexander Pyron
Tegus of the genera Tupinambis and Salvator are the largest Neotropical lizards and the most exploited clade of Neotropical reptiles. For three decades more than 34 million tegu skins were in trade, about 1.02 million per year. The genus Tupinambis is distributed in South America east of the Andes, and currently contains four recognized species, three of which are found only in Brazil. However, the type species of the genus, T. teguixin, is known from Bolivia, Brazil, Colombia, Ecuador, French Guyana, Guyana, Peru, Suriname, Trinidad and Tobago, and Venezuela (including the Isla de Margarita). Here we present molecular and morphological evidence that this species is genetically divergent across its range and identify four distinct clades some of which are sympatric. The occurrence of cryptic sympatric species undoubtedly exacerbated the nomenclatural problems of the past. We discuss the species supported by molecular and morphological evidence and increase the number of species in the genus Tupinambis to seven. The four members of the T. teguixin group continue to be confused with Salvator merianae, despite having a distinctly different morphology and reproductive mode. All members of the genus Tupinambis are CITES Appendix II. Yet, they continue to be heavily exploited, under studied, and confused in the minds of the public, conservationists, and scientists.
Ecological Entomology | 2016
Fernando Amor; Irene Villalta; Claudie Doums; Elena Angulo; Stéphane Caut; Sara Cecilia Díaz Castro; Michael J. Jowers; Xim Cerdá; Raphaël Boulay
1. In many ant species, caste differentiation stems from trophic differences at the larval stage. Adult workers that feed larvae have great control over the allocation of colony resources to growth (production of workers) versus reproduction (production of queens). However, larval caste fate may also be constrained very early on through direct genetic effects or non‐genetic maternal effects.
Systematics and Biodiversity | 2015
Michael J. Jowers; Ahmed Taheri; Joaquín Reyes-López
Anochetus ghilianii is the only species of the genus Anochetus found in Europe. Its presence in the southernmost region of the Iberian Peninsula (Province of Cadiz) is puzzling. Anochetus ghilianiis poor dispersal capabilities (colony foundation by foot and wingless queens) suggest that its presence in the Iberian Peninsula must be ancient, dating to from at least the last connection period between both Spain and Africa around 5 million years ago. In the Iberian Peninsula, this species is only found at low altitude coastal localities, whereas its mainland counterpart populations of North Morocco show a more widespread distribution, also found at higher altitude inland. In this study, we sequenced a fragment of a rapidly evolving mitochondrial gene (COI) from several individuals throughout the species Moroccan and Iberian distribution range. The results from the Bayesian Inference (BI) and Median-Joining analyses showed a genetic pattern of decreasing haplotypic diversity from southern to northern localities. Furthermore, our results recovered the same haplotype from all the Iberian localities and from Cap Spartel and Tangier in North Morocco. We attribute this lack of genetic divergence to multiple reoccurring translocations through maritime traffic between ports on either side of the Strait of Gibraltar. Our study raises the concern that two other ants, Technomyrmex vexatus and Stigmatomma emeryi, also believed to be Tertiary relicts with a similar distribution pattern to A. ghilianii, may have also been introduced accidentally in the Iberian Peninsula.
PeerJ | 2017
Amaël Borzée; Joana L. Santos; Santiago Sánchez-Ramírez; Yoonhyuk Bae; Kyongman Heo; Yikweon Jang; Michael J. Jowers
The effects of ice ages on speciation have been well documented for many European and North American taxa. In contrast, very few studies have addressed the consequences of such environmental and topographical changes in North East Asian species. More precisely, the Korean Peninsula offers a unique model to assess patterns and processes of speciation as it hosts the northern- and eastern-most distribution limit of some widespread Asian taxa. Despite this, studies addressing phylogeographic patterns and population genetics in the peninsula and surrounding countries are few and studies for most families are lacking. Here we inferred the phylogenetic relationships of the common toad (Bufo gargarizans) from South Korea and their North East Asian counterpart populations, based on mitochondrial data. Korean B. gargarizans GenBank BLASTs matched few individuals from nearby China, but the presence of a Korean clade suggests isolation on the Korean Peninsula, previous to the last glacial maximum, linked to sea level resurgence. Molecular clock calibrations within this group were used to date the divergence between clades and their relationship to paleo-climatic events in the area. Lack of genetic structure among South Korean populations and strong homogeneity between the Korean and some Chinese localities suggest weak isolation and recent expansion. Geographical projection of continuous coalescent maximum-clade-credibility trees shows an original Chinese expansion towards the Korean Peninsula through the Yellow Sea circa two million years ago with colonisation events dating circa 800 thousand years ago (K. y. a.). Following this colonisation, the data point to outgoing Korean Peninsula dispersal events throughout different periods, towards the North through land, and West through land bridge formations over the Yellow Sea during sea level falls. In accordance, demographic analyses revealed a population expansion in the Koran Peninsula circa 300 K. y. a., likely attributed to glacial cycle fluctuations.
Experimental and Applied Acarology | 2017
David Ndeereh; Gerald Muchemi; Ag Thaiyah; Moses Otiende; Samer Angelone-Alasaad; Michael J. Jowers
Coxiella burnetii is the causative agent of Q fever, a zoonotic disease of public health importance. The role of wildlife and their ticks in the epidemiology of C. burnetii in Kenya is unknown. This study analysed the occurrence and prevalence of the pathogen in wildlife and their ticks at two unique wildlife–livestock interfaces of Laikipia and Maasai Mara National Reserve (MMNR) with the aim to determine the potential risk of transmission to livestock and humans. Blood from 79 and 73 animals in Laikipia and MMNR, respectively, and 756 and 95 ixodid ticks in each of the areas, respectively, was analysed. Ticks were pooled before analyses into 137 and 29 samples in Laikipia and MMNR, respectively, of one to eight non-engorged ticks according to species and animal host. Real-time PCR amplifying the repetitive insertion element IS1111a of the transposase gene was used to detect C. burnetii DNA. Although none of the animals and ticks from MMNR tested positive, ticks from Laikipia had an overall pooled prevalence of 2.92% resulting in a maximum-likelihood estimate of prevalence of 0.54%, 95% CI 0.17–1.24. Ticks positive for C. burnetii DNA belonged to the genus Rhipicephalus at a pooled prevalence of 2.96% (maximum-likelihood estimate of prevalence of 0.54%, 95% CI 0.17–1.26). These ticks were Rhipicephalus appendiculatus, R. pulchellus and R. evertsi at pooled prevalence of 3.77, 3.03 and 2.04%, respectively. The presence of C. burnetii in ticks suggests circulation of the pathogen in Laikipia and demonstrates they may play a potential role in the epidemiology of Q fever in this ecosystem. The findings warrant further studies to understand the presence of C. burnetii in domestic animals and their ticks within both study areas.
Oryx | 2016
Stéphane Caut; Michael J. Jowers
The Caribbean Islands are a biodiversity hotspot where anthropogenic disturbances have had a significant impact, causing population declines and extinction of endemic species. The ground snake Erythrolamprus cursor is a dipsadid endemic to Martinique; it is categorized as Critically Endangered on the IUCN Red List and is known only from museum specimens. The snake was common on Martinique during the 18th and 19th centuries but there have been no reliable sightings since 1968, suggesting it may have gone extinct, probably as a result of the introduction of the small Indian mongoose Herpestes javanicus auropunctatus . However, the islet known as Diamond Rock, south-west of Martinique, is mongoose-free and the last reported sighting of E. cursor there was in 1968. The islet was last occupied during the Napoleonic Empire (the early 19th century), is now completely protected, and is difficult to access (it spans 5.8 ha, with a maximum elevation of 175 m). We conducted the first extensive survey of the islet, over 10 days, to clarifty the status of E. cursor . Our study revealed that unique conditions exist on Diamond Rock (i.e. aridity and a distinct potential prey community) and that E. cursor would have had to modify its ecology to persist on the islet. Although the rugged terrain of Diamond Rock makes it difficult to explore, it is probable that E. cursor is now extinct.
Parasitology Research | 2018
Jesus Díaz-Rodríguez; David Donaire-Barroso; Michael J. Jowers
In this study, we report, through molecular identification, the first African records of a digenean trematode parasite of the genus Euryhelmis. We recovered metacercariae encysted in an anuran, the endemic Moroccan painted frog (Discoglossus scovazzi), and a vulnerable caudate, the North African fire salamander (Salamandra algira), from four localities in North Africa (Morocco). Our records go back to the past century and have been confirmed in successive fieldwork seasons thereafter. Metacercarial stages of these parasites require amphibians as the last intermediate host, but the exact identity of the primary hosts and predators of the infected animals in Africa remain unknown. Our searches with basic local alignment search tool (BLAST) from Genbank revealed that hosts were infected by parasites of Euryhelmis costaricensis, which showed almost the same genetic identity (with only one substitution) to previous reports from Costa Rica and Japan, suggesting a recent introduction in Morocco. We proceed to discuss the likely role of introduced mustelids as the potential definitive hosts of trematode adults. Under this assumption, we conclude that the infestation of Discoglossus scovazzi and Salamandra algira might pose a risk to these threatened species.
BMC Genetics | 2018
Samer Angelone; Michael J. Jowers; Anna Rita Molinar Min; Paulino Fandos; Paloma Prieto; Mario Pasquetti; Francisco Javier Cano-Manuel; Gregorio Mentaberre; Jorge Ramón López Olvera; Arián Ráez-Bravo; José Espinosa; Jesús M. Pérez; Ramón C. Soriguer; Luca Rossi; José E. Granados
BackgroundDefining hidden genetic diversity within species is of great significance when attempting to maintain the evolutionary potential of natural populations and conduct appropriate management. Our hypothesis is that isolated (and eventually small) wild animal populations hide unexpected genetic diversity due to their maintenance of ancient polymorphisms or introgressions.ResultsWe tested this hypothesis using the Iberian ibex (Capra pyrenaica) as an example. Previous studies based on large sample sizes taken from its principal populations have revealed that the Iberian ibex has a remarkably small MHC DRB1 diversity (only six remnant alleles) as a result of recent population bottlenecks and a marked demographic decline that has led to the extinction of two recognized subspecies. Extending on the geographic range to include non-studied isolated Iberian ibex populations, we sequenced a new MHC DRB1 in what seemed three small isolated populations in Southern Spain (nu2009=u2009132). The findings indicate a higher genetic diversity than previously reported in this important gene. The newly discovered allele, MHC DRB1*7, is identical to one reported in the domestic goat C. aegagrus hircus. Whether or not this is the result of ancient polymorphisms maintained by balancing selection or, alternatively, introgressions from domestic goats through hybridization needs to be clarified in future studies. However, hybridization between Iberian ibex and domestic goats has been reported in Spain and the fact that the newly discovered allele is only present in one of the small isolated populations and not in the others suggests introgression. The new discovered allele is not expected to increase fitness in C. pyrenaica since it generates the same protein as the existing MHC DRB1*6. Analysis of a microsatellite locus (OLADRB1) near the new MHC DRB1*7 gene reveals a linkage disequilibrium between these two loci. The allele OLADRB1, 187xa0bp in length, was unambiguously linked to the MHC DRB1*7 allele. This enabled us to perform a DRB-STR matching method for the recently discovered MHC allele.ConclusionsThis finding is critical for the conservation of the Iberian ibex since it directly affects the identification of the units of this species that should be managed and conserved separately (Evolutionarily Significant Units).
Studies on Neotropical Fauna and Environment | 2016
John C. Murphy; Mike G. Rutherford; Michael J. Jowers
ABSTRACT The confusion between the Neotropical threadsnakes Epictia albifrons (Wagler) and Epictia tenella (Klauber) has been ongoing for decades. The lost holotype of Stenostoma albifrons, a poorly detailed original description, and dubious type locality confound the problem. Recently an extant series of nine museum specimen from Belém, state of Pará, Brazil were selected as topotypes for Epictia albifrons Wagler. From this series a neotype was designated. Here we compare the morphology of the neotype to specimens from Trinidad and Guyana, confirming that they are Epictia tenella (Klauber) not E. albifrons (Wagler). We also compare four mitochondrial and one nuclear marker from Trinidad and mainland (Guyana) Epictia tenella populations and find E. tenella relatively widespread with minimal genetic diversification between island and mainland specimens. Hypotheses that may explain the low divergence for this small, fossorial snake are explored and discussed: over-water rafting, human-mediated dispersal, and avian-mediated dispersal.