Laurent Granjon

Institute of Research for Development | IRD · 022 - Biology centre for population management (CBGP)

Population genetic approaches may be used to investigate dispersal patterns of species living in highly urbanized environment in order to improve management strategies for biodiversity conservation or pest control. However, in such environment, population genetic structure may reflect both current features of the cityscape and urbanization history....

Previous field-based studies have evidenced patterns in gastrointestinal helminth (GIH) assemblages of rodent communities that are consistent with “enemy release” and “spill-back” hypotheses, suggesting a role of parasites in the ongoing invasion success of the exotic house mouse ( Mus musculus domesticus ) in Senegal (West Africa). However, these...

Describing patterns and testing hypotheses on processes driving biological invasions represent major issues in ecology. Addressing these questions requires building adequate data sets, i.e. covering areas and spanning periods adapted to the invasion processes studied. Rodents include major invasive species, among which the black rat Rattus rattus a...

En observant et analysant la propagation du rat noir (Rattus rattus) au Sénégal, cet ouvrage souligne la dynamique spatiale d'un réservoir animal emblématique de zoonoses. Dans les confins orientaux du territoire sénégalais, ce rongeur commensal profite de la transformation des environnements et de la croissance des échanges marchands pour s'instal...

Murine rodents are one of the most evolutionary successful groups of extant mammals. They are also important for human as vectors and reservoirs of zoonoses and agricultural pests. Unfortunately, their fast and relatively recent diversification impedes our understanding of phylogenetic relationships and species limits of many mu-rine taxa, includin...

Relationships between parasitism and invasion success are increasingly evidenced in the literature. However, the dynamic nature of the major parasite-related processes has been rarely taken into account until now, while the residence time of invaders in colonized regions was shown to be associated to crucial changes in parasite communities. Here, w...

Hantaviruses cause hemorrhagic fever in humans worldwide. However, few hantavirus surveillance campaigns occur in Africa. We detected Seoul orthohantavirus in black rats in Senegal, although we did not find serologic evidence of this disease in humans. These findings highlight the need for increased surveillance of hantaviruses in this region.

Rodents are known to be reservoir hosts for at least 60 zoonotic diseases and are known to play an important role in their transmission and spread in different ways. We sampled different rodent communities within and around human settlements in Northern Senegal, an area subjected to major environmental transformations associated with global changes...

Bartonella saheliensis strain 077 (= CSUR B644T; = DSM 28003T) is a new bacterial species isolated from the rodent Gerbilliscus gambianus blood captured in the Sine-Saloum region of Senegal. In this work we describe both the characteristics of this microorganism, as well as the complete sequence of the genome and simultaneously its annotation. Its...

Rodents are known to be reservoir hosts for at least 60 zoonotic diseases and are known to play an important role in their transmission and spreading in different ways. We sampled different rodent communities within and around human settlements in Northern Senegal, an area subjected to major environmental transformations associated with global chan...

Gerbillus nigeriae is a sand-dwelling and semi-arid adapted rodent species restricted to the West African Sahel where it causes extensive damages to cereal crops such as millet and sorghum. It also displays one of the most extensive floating chromosomal polymorphisms currently known in mammals, showing a non-random spatial distribution of diploid n...

Population genetics of human commensal species within cities may reflect current features of the cityscape, including socio-economic aspects, as well as urbanization history. Understanding genetic structure of archetypal commensals such as rodent pests may provide useful insights to manage their populations. In this study, we addressed these issues...

The Biological Resource Centre for the Environment BRC4Env is a network of Biological Resource Centres (BRCs) and collections whose leading objectives are to improve the visibility of genetic and biological resources maintained by its BRCs and collections and to facilitate their use by a large research community, from agriculture research to life s...

Murid rodents (Rodentia: Muridae) represent the most diverse and abundant mammalian family. In this study, we provide a refined set of fossil calibrations which is used to reconstruct a dated phylogeny of the family using a multilocus dataset (six nuclear and nine mitochondrial gene fragments) encompassing 161 species representing 82 murid genera f...

The publisher wishes to correct the following error which was introduced during the production of this manuscript. The protologue of the Bartonella mastomydis contained several misprints and inaccuracies. The corrected version of the protologue is as follows: Description of Bartonella mastomydis sp. nov. strain 008: Bartonella mastomydis (mas.to′my...

Dated phylogeny for family Muridae.

Bartonella mastomydis sp. nov. strain 008 is the type strain of B. mastomydis sp. nov., a new species within the genus Bartonella. This strain was isolated from Mastomys erythroleucus rodents trapped in the Sine-Saloum region of Senegal. Here we describe the features of this organism, together with the complete genome sequence and its annotation. T...

Parmi les rongeurs, le genre Gerbillus emblématique des zones arides de l’Ancien-Monde se caractérise par une forte diversité spécifique. Toutefois, les relations de parenté entre ses espèces sont mal connues, de même que son histoire évolutive. L’analyse de données de séquences moléculaires sur un échantillon représentatif d’espèces a permis de mo...

Murid rodents (Rodentia: Myomorpha: Muroidea: Muridae) represent the most diverse and abundant mammalian group. In this study, we reconstruct a dated phylogeny of the family using a multilocus dataset (six nuclear and nine mitochondrial gene fragments) encompassing 160 species representing 82 distinct murid genera from four extant subfamilies (Deom...

There are two main factors explaining variation among species and the evolution of characters along phylogeny: adaptive change, including phenotypic and genetic responses to selective pressures, and phylogenetic inertia, or the resemblance between species due to shared phylogenetic history. Phenotype-habitat colour match, a classic Darwinian exampl...

Wesselsbron disease is a neglected mosquito transmitted Flavivirus infection that causes abortions and has teratogenic effects on sheep and cattle in Africa. Human can also be infected. The detection of human or animal cases is complicated by the non-specific symptoms close to Rift Valley Fever (RVF) in domestic livestock species or Dengue like syn...

The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used t...

In the contemporary context of zoonosis emergence and spread, invasive species are a major issue since they represent potential pathogen hosts. Even though many progresses have been done to understand and predict spatial patterns of invasive species, the challenge to identify the underlying determinants of their distribution remains a central quest...

The systematics of the arid-adapted Old World Gerbillus rodent genus has always been challenging, with many different taxonomic arrangements proposed. Beyond such taxonomic aspects, the timing and geographical pattern of the evolutionary history of this group remains largely unknown. Based on mitochondrial (cytochrome b) and nuclear (interphotorece...

In Southeastern Senegal, health concerns are raised regarding the invasion of the Black Rat, a commensal species and a host of pathogens. The historical invasion of this rodent in Senegal shows the combination of both bioecological and anthropogenic factors, including climate variability. From this historical point of view, appearance and disappear...

Methodological improvements now allow routine analyses of highly degraded DNA samples as found in museum specimens. Using these methods could be useful in studying such groups as rodents of the genus Gerbillus for which i) the taxonomy is still highly debated, ii) collection of fresh specimens may prove difficult. Here we address precise taxonomic...

Gerbillus nigeriae est un rongeur inféodé aux zones sèches du Sahel où il occasionne d"importants dégâts sur les cultures. L"espèce se caractérise également par un polymorphisme chromosomique exceptionnel avec une gamme de variation des nombres diploïdes 2N s"étendant de 60 à 74 chromosomes. Afin de tester des corrélations entre ce polymorphisme ch...

Tick-borne Relapsing Fever (TBRF) is a zoonotic disease caused by several Borrelia species transmitted to humans by Ornithodoros tick vectors. In West Africa, Borrelia crocidurae is a common cause of disease in many rural populations. Small mammals act as reservoirs of infection. We report here the results of surveys that investigated the occurrenc...

The worldwide intensification of human‐associated exchanges favours the multiplication of biological invasions. Among mammals, rodent species, including the house mouse M us musculus, are identified as major invaders with profound impacts on native biodiversity, human health and activities. Though contemporary rodent invasions are described on seve...

KEY WORDS Herein we review available information on the bat fauna of Burkina Faso, synthesizing data on a considerable number of museum specimens collected in the country between 1964 and 2010. We aim to give an exhaustive review of the locally occurring taxa and their distribution overlaid on different phytogeographic areas. To achieve this object...

A phylogeographic study was conducted on the Nile grass rat, Arvicanthis niloticus, a rodent species that is tightly associated with open grasslands from the Sudano-Sahelian regions. Using one mitochondrial (cytochrome b) and one nuclear (intron 7 of Beta Fibrinogen) gene, robust patterns were retrieved that clearly show that (i) the species origin...

Relapsing fever is the most frequent bacterial disease in Africa. Four main vector / pathogen complexes are classically recognized, with the louse Pediculus humanus acting as vector for B. recurrentis and the soft ticks Ornithodoros sonrai, O. erraticus and O. moubata acting as vectors for Borrelia crocidurae, B. hispanica and B. duttonii, respecti...

Pterygodermatites (Mesopectines) quentini n. sp. (Nematoda, Rictulariidae) is described from the murine host Praomys rostratus in the south of the Republic of Mali. It differs from other species of the subgenus by the morphology of the head, which bears four simple cephalic papillae and a nearly axial oral opening, the number of caudal papillae, th...

The small-mammal community of a typical Sudanian savannah area of south-eastern Senegal was studied by way of intensive sampling at the beginning (July) and at the end (November) of the rainy season. A total of 5931 trapnights and 200 pitfallnights yielded 767 small mammals, including 757 rodents of 12 species, as well as a few shrews and hedgehogs...

In order to evaluate the contribution of geological, environmental, and climatic changes to the spatial distribution of genetic variation of Mastomys natalensis, we analysed cytochrome b sequences from the whole distribution area of the species to infer its phylogeographic structure and historical demography. Six well-supported phylogroups, differe...

Abstract A new species of the genus Oxynema Linstow, 1899 is described from the African sciurids Xerus erythropus and Heliosciurus gambianus. Oxynema xerusi n. sp. is characterized by lacking cervical and caudal alae, and by having unequal spicules. It differs from the closest species, Oxynema linstowi Deshmukh, 1987 and O. bioccai Campana-Rouget,...

In order to evaluate the contribution of geological, environmental, and climatic changes to the spatial distribution of genetic variation of Mastomys natalensis, we analysed cytochromeb sequences from the whole distribution area of the species to infer its phylogeographic structure and historical demography. Six well-supported phylogroups, differen...

Thirteen microsatellite loci for the threatened orange coral, Astroides calycularis have been designed. The polymorphism of these thirteen loci was tested in 24 polyps from different colonies. The results show that the allele numbers for each loci ranged from 2 to 14 (mean Na=5.1), with an average observed heterozygosity of 0.47 (He=0.45). These ne...

The systematics of the rodent genus Gerbillus still needs clarifications. Within this genus, Gerbillus nanus is a species often considered to have a wide geographic distribution ranging from northwest India to the Mauritanian coast. Some authors, however, have suggested that other species, namely Gerbillus amoenus and/or Gerbillus garamantis , may...

Knowledge of the biology of the trichinelloid subfamily Trichosomoidinae is poor. Trichosomoides nasalis is a common parasite of Arvicanthis niloticus (Muridae) in Senegal, and a procedure for experimental infections has been established. It has been demonstrated that larvae develop in striated muscle fibres, similar to Trichinella spp., but they a...

The presence in Morocco of Argasid ticks of the Ornithodoros erraticus complex, the vector of tick-borne relapsing fever (TBRF) in North Africa, has been known since 1919, but the disease is rarely diagnosed and few epidemiological data are available. Between 2006 and 2011, we investigated the presence of Ornithodoros ticks in rodent burrows in 34...

The lesser Egyptian jerboa Jaculus jaculus is a desert dwelling rodent that inhabits a broad Arabian–Saharan arid zone. Recently, two distant sympatric lineages were described in North-West Africa, based on morphometric and molecular data, which may correspond to two cryptic species. In the current study, phylogenetic relationships and phylogeograp...

The systematics of the African rodent genus Gerbilliscus is still a matter of debate. At the genus level it has been said to include the related genus Gerbillurus, and at the species level some species still need to be definitely recognized as distinct. To tackle these questions, we gathered and analyzed mitochondrial (cytochrome b) and nuclear (BR...

The Mediterranean Basin is an acknowledged hotspot for biodiversity, yet historical processes that shaped this biodiversity in North Africa remain poorly understood. This study aimed to elucidate the phylogeographic pattern of an endemic species of Mediterranean areas of North Africa, the Greater Egyptian Jerboa, Jaculus orientalis. The extent of p...

Gerbils of the genus Gerbillus represent an important part of small mammal diversity in arid regions of North Africa, but their taxonomy and evolutionary systematics and biogeography are still poorly known. Based on the recent collection of a series of gerbils in southern Morocco, including at the type localities of three endemic species, we gather...

The lesser Egyptian jerboa Jaculus jaculus is a desert dwelling rodent that inhabits a broad Arabian–Saharan arid zone. Recently, two distant sympatric lineages were described in North-West Africa, based on morphometric and molecular data, which may correspond to two cryptic species. In the current study, phylogenetic relationships and phylogeograp...