Meriones Species Research Articles

Let us go back to the type materials to investigate the cranial differences among the Meriones species (Rodentia, Gerbillinae)

Let us go back to the type materials to investigate the cranial differences among the Meriones species (Rodentia, Gerbillinae)

Genetic Identification of Meriones spp. The Reservoir Host of Cutaneous Leishmaniasis in the North Western Region of Libya

The identification and classification of reservoir hosts of zoonotic cutaneous leishmaniasis are very crucial towards the integrated management and control planning. Molecular techniques have been deployed and showed very sensitive and specific results to identify and differentiate rodents with great similarity in phenotypes including Meriones spp. Meriones species are very difficult to distinguish and separate according to their morphology and phenotype traits. This study was carried out in western region of Libya and three Meriones rodents were collected and their genetic identification was conducted by PCR technique using designed forward and reverse primers from Meriones spp. cytochrome b (cytb) gene sequence. This study has differentiated three haplotypes of M. shawi. with sequences similarities between samples of haplotypes were 99.13%, 99.42% and 99.71% between H1 and H2, between H1 and H3 and between H2 and H3 respectively. The current work is the first to use molecular techniques to study the genetic sequence of Meriones in Libya and has illustrated that PCR technique is powerful tool to discriminate Meriones species in western region of Libya.

The Role of Postcranial Skeleton Morphology in Species Identification and Phylogeny Inferences: Gerbillinae (Rodentia: Muridae) as a Case Study

Identification of rodents usually has been done based on cranial and dental characters. Postcranial skeleton has been ignored in spite of its importance in archaeozoology for identification of skeletal remains. Herein, we intended to determine the importance of postcranial skeleton in identification and classification of gerbilline rodents in Iran. Different skeletal parts of 82 specimens belonged to five genera and ten species were extracted using papain digestion. A total of 62 characters with 142 character states were defined as informative postcranium variations for separating taxa. Results showed that reconnaissance of specimens belonging to the genera Tatera, Gerbillus, and Rhombomys was possible using morphological characters of vertebral column and thorax, pectoral girdle and forelimb, and pelvic girdle and hindlimb. Moreover, these morphological characters could be useful for identification of Meriones species. For cladistic analyses, the data matrix scored for two characters of external anatomy, 20 of vertebral column, 11 of pectoral girdle, seven of pelvic girdle, ten of forelimb and 12 of hindlimb was provided. The cladogram resulted from strict consensus method, employed in PHYLIP, was comparable with phylogenetic trees inferred from cranial morphology and molecular studies. Finally, an identification key for Gerbillinae was provided based on postcranium characteristics.

Sexual dimorphism, allometry, and interspecific variation in the cranial morphology of seven Meriones species (Gerbillinae, Rodentia)

Sexual dimorphism, allometry, and interspecific variation in the cranial morphology of seven Meriones species (Gerbillinae, Rodentia)

Testing and quantification of cranial shape and size variation within Meriones hurrianae (Rodentia: Gerbillinae): A geometric morphometric approach

The Indian Jird, Meriones hurrianae, is unusual among the family Gerbillidae in not being from desert or sub-desert habitats, and in its ability to endure cold weather. Therefore, the distribution range of the Indian jird has no overlap with other species of Meriones. The habitat of the Indian jird is increasingly fragmented, so that this species is increasingly under threat. The ecology of this species, as well as its morphology, is poorly known. The present study, using a two-dimensional landmark-based geometric morphometric approach, aims to investigate intraspecific variation in skull shape and size of populations of this species. For this purpose, more than 50 skull specimens coming from different localities along the distribution range of this species were analyzed. The results allow us to reject the hypothesis that there would be no significant difference in skull shape and size. For instance, some specimens, such as those from Bandar Abbas (Iran), show significant shape differences compared with others. Differences were also significant for some size characteristics, e.g. cranium size and length, as well as the size of the auditory bulla. The observed morphological variation is discussed in the context of taxonomy and conservation of the Indian Jirds.

Genetic diversity within two Tunisian wild jirds: Meriones shawi and Meriones libycus (Rodentia, Gerbillinae)

Three Meriones species inhabit Tunisia, namely M. shawi, M. libycus and M. crassus, but little genetic data exist on these gerbils. We collected Meriones from eight localities in Tunisia, and obtained mitochondrial (cytochrome b) and nuclear (IRBP) gene sequence data for 37 and 13 specimens, respectively, belonging to two species: M. shawi and M. libycus. We also optimised three microsatellite markers previously described in M. unguiculatus to obtain a finer analysis of their genetic diversity and geographic structure, given their wide distribution. Phylogenetic inferences of cyt b and IRBP data for these species, in the context of other gerbillin data, corroborate their taxonomic affinities reported by previous studies. High cyt b haplotype diversity was observed in both species (25 haplotypes in 29 and 27 sequences for M. shawi and M. libycus, respectively) with little geographical structure for M. shawi but three divergent groups in M. libycus. The average microsatellite diversity within each population was high (HO ≥ 0.6, HE ≥ 0.8) with M. libycus populations attaining the highest values. Population differentiation was moderate for several population pairs (Fst ≥ 0.1), the highest being between M. shawi populations. However, genetic distance among populations was not significantly correlated with geographic distance in either M. shawi or M. libycus. Our results contribute to a better characterisation of Tunisian Meriones species, suggesting high geographic structure in mtDNA of M. libycus populations within North Africa.

The distribution of mucous secreting cells in the gastrointestinal tracts of three small rodents from Saudi Arabia: Acomys dimidiatus, Meriones rex and Meriones libycus

The proportion of mucin phenotypes (which form the protective biofilm of the gastrointestinal tract) differs between intestinal regions. This study examines the distribution of mucin secreting cells in the gastrointestinal tracts of the Eastern spiny mouse (Acomys dimidiatus), King jird (Meriones rex) and Libyan jird (Meriones libycus), which inhabit the dry and hot deserts of Saudi Arabia. Intestinal tract samples were processed to wax and tissue sections stained with Alcian Blue-Periodic Acid Schiff (AB-PAS) and High Iron Diamine-Alcian Blue (HID-AB) in order to determine different mucin phenotypes by quantitative analysis. Mixed mucin secreting cells (combined neutral and acid) was the predominant mucin secreting cell type observed throughout the gastrointestinal tract in all species. Acid mucin secreting goblet cells were mainly located in the colon. A. dimidiatus presented with significantly more total sialo than sulfomucin secreting cells while the opposite was true for both Meriones species. The distribution of mucin secreting cells is therefore similar to previously reported results for small mammals not living under arid conditions.

Low diversity of Leishmania parasites in sandflies and the absence of the great gerbil in foci of zoonotic cutaneous leishmaniasis in Fars province, southern Iran

Fars province lies to the south of the main foci of zoonotic cutaneous leishmaniasis (ZCL) caused by Leishmania major in central and northern Iran, and its ZCL foci might have emerged more recently because of different transmission cycles. However, there have been limited studies of the parasites infecting the regional sandfly vectors. The diversities of sandflies and the Leishmania parasites infecting female sandflies were assessed for different habitats in Fars ZCL foci, 2008-2009, using standardized sandfly trapping and characterization of ribosomal DNA haplotypes of parasites. Vector diversity was similar to that in the main Iran ZCL foci, but parasite diversity was lower. Only Le. major was detected in Fars sandflies. Most infections were found in the abundant vector Phlebotomus papatasi collected in rodent burrows. Infections were detected for the first time in Iran in the related P. bergeroti. The failure to detect other gerbil parasites (Le. turanica, Le. gerbilli) is explained by the absence of one reservoir host, the great gerbil Rhombomys opimus. Other gerbils (Meriones species) may be the regional reservoir hosts, but transmission modelling is required for a better understanding of the emergence and stability of ZCL foci in Fars and other Iranian provinces.

Morphological comparison of fourteen species of the genus Meriones Illiger, 1811 (Rodentia: Gerbillinae) from Asia and North Africa

Genus Meriones is the dominant member of gerbils in the Palaearctic region, particularly in aride region of Asia. This is also one of the most typical genus of subfamily Gerbillinae with about 17 morphospecies namely: M. persicus, M. hurrianae, M. zarudnyi M. vinogradovi, M. meridianus, M. libycus, M. crassus, M. tristrami, M. rex, M. tamariscinus, M. unguiculatus, M. shawi, M. grandis, M. sacramenti, M.dahli, M.chengi, M.arimalius . Of which first eight species have been recorded from the Iranian Plateau. There are minor differences between some species and hence, interspecific discrimination of specimens from each species is not always possible, even by polytechnic methods using different taxonomic characters such as tympanic bullae, suprameatal triangle and external characters on material from museums and dental characters on archeozoological materials. Here, 26 morphological characters of 384 museum specimens belonging to 14 morphospecies of Meriones from North Africa, Iran and Central Asia were studied. This study review, 14 species of Meriones and based on the results, it seems that M.libycus, M. crassus and M. meridianus are complex species and need taxonomic revision. The cladistics analysis shows that M. vinogradovi could be forming ancestral species of genus Meriones, and west of Caspian Sea could be the center of origin for Meriones. Due to the presence of convergence regarding adaptation of different species of Meriones to similar environment, subgeneric morphological characters may cause homoplasies and paraphyletic subgenera the analysis of morphological character states matrix, using Mix program of Phylip shows different four clades that did not conform to the nominative subgenera and unveil probable homoplasy.

Molecular Phylogeny of the Subfamily Gerbillinae (Muridae, Rodentia) with Emphasis on Species Living in the Xinjiang-Uygur Autonomous Region of China and Based on the Mitochondrial Cytochromeband CytochromecOxidase Subunit II Genes

Rodents belonging to the subfamily Gerbillinae and living in the Xinjiang-Uygur autonomous region of China were collected in field surveys between 2001 and 2003. We found four Meriones species, including M. chengi M. liycus, M. meridianus, and M. tamariscinus, as well as related species from different genera, Rhombomys opimus and Brachiones przewaliskii For phylogenetic analyses of these gerbilline species, DNA sequences of parts of the mitochondrial cytochrome b (Cytb) and cytochrome c oxidase subunit II (COII) genes were examined with the neighbor Joining, maximum parsimony, maximum likelihood, and Bayesian inference methods. Our phylogenetic analyses suggest that the genus Meriones is not monophyletic and place M. tamaricinus as the sister taxon to a clade comprising Brachiones, Psammomys, Rhombomys, and the other Meriones species. The remaining Meriones species separate into three lineages: M. meridianus (including M. chengi), Meriones unguiculatus, and a clade that includes multiple Meriones species originating from Asia, the Middle East, and Africa. The phylogenetic relationships among the genera Brachines, Meriones, Psammomys, and Rhombomys remain ambiguous, probably due to the saturation of mutations that occurs in fast-evolving mitochondrial DNA. In addition, intraspecific variation was observed for M. meridianus, and this mostly correlated with collection localities, i.e., the northern and southern parts of the Xinjiang region. This variation corresponded to interspecific levels of divergence among other lineages of Meriones. Interestingly, no differences were observed in either the Cytb or COII gene sequences isolated from M. chengi collected from the Turfan Basin in the north and those from M. meridianus in the south, suggesting that M. chengi may be a synonym of M. meridianus.

Elliptic Fourier analysis on the tympanic bullae in three Meriones species (Rodentia, Mammalia): its application in biosystematics

Abstract. The size and shape of the auditory bullae are investigated across three species of Meriones, in order to determine the biosystematic value of bulla characteristics in species recognition. This study is based on outline (geometric morphometric) with elliptical Fourier and eigenshape analysis of tympanic bullae in: (a) the suprameatal triangle, (b) the mastoid, (c) the auditory meatus, and (d) the ventral view of bullae. The results show that characters of the auditory meatus separate these three species from each other. The shape of different parts of the bullae within each species is also shown to vary such as in two populations of M. persicus. The shape of organs is important in the interaction between the organism and its environment. Tympanic bullae variation is similar in the Geno population of M. persicus (Geno is located in south of Iran), and in M. libycus which lives in similar climates. The results of this analysis of tympanic bullae differ from the characters described by CORBET (1978).

Diagnostic Characters and Distribution of Meriones Illiger, 1811 Species (Mammalia: Rodentia) in Turkey

In this study, specimens of Meriones collected from various areas of Turkey were evaluated based on morphological and biometrical characters. It was determined that four species; Meriones tristrami, Meriones vinogradovi, Meriones meridianus and Meriones crassus exist in Turkey. External characters such as the terminal tuft on tail, the colour of ventral hairs, the soles of hind foot and the length of tail, and cranial characters such as the structure of suprameatal triangle, the connection of anterior rim of auditory meatus to squomosal and the projection of mastoid portion of tympanic bullae from supraoccipitals were determined to be useful in distinguishing species of Meriones. The range of M. tristrami in steppes and plains below altitude of 1200 m in Anatolia, M. vinogradovi in vicinity of Kars and Iğdır province, M. meridianus at sandy belts in the north of Ağrı mountain and M. crassus in Southeastern Anatolia were determined.

Course of Infection and Humoral Response to Leishmania major in Inbred Meriones unguiculatus

Numerous species of Meriones have been incriminated as natural reservoir hosts of Leishmania major in Mongolia, Soviet Asia, Afghanistan, the Middle East, and North Africa. However, little is known about the immunological response or course of infection in these small rodents. In this study, 40 commercially obtained inbred Meriones unguiculatus were divided into equal groups and injected in the right hind footpad with various doses of L. major promastigotes or with medium only. At regular intervals, blood was collected from the animals for subsequent evaluation of the kinetics of anti-L. major serum antibody production. Footpad lesions were measured periodically for 13 wk, beginning just before infection. The humoral response to infection and the course and severity of disease were dose related. However, metastasis lymph nodes, liver, spleen, and secondary cutaneous sites occurred at each of the doses tested.