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Due to its faster evolution rate compared to nuclear genes, haploid mitochondrial DNA (mtDNA) is a promising species identification tool. This has led to its significant use in taxonomic and phylogenetic studies. While mtDNA is subject to selective constraints that prevent the accumulation of deleterious mutations, the prevalence of nuclear-mitochondrial fragments (known as NUMTs or pseudogenes) in mammals has complicated the use of mtDNA for taxonomy. In the present study, a pseudogene of the mitochondrial cytochrome b (Cytb) was detected in Meriones persicus. This pseudogene differed from its mitochondrial counterpart at 235 out of 1140 sites and is characterized by frame-shift mutations, indels, and accumulation of non-synonymous substitutions. It is the first report of the Cytb pseudogene in a jird, highlighting the risk of misidentifying NUMTs as authentic mtDNA and the importance of addressing this potential pitfall in taxonomic studies. [ABSTRACT FROM AUTHOR]

Simple Summary: In the present study, we tested whether, when given the choice to ascend or descend, rodents would favor traveling downwards or upwards on identical inclinations and sought to explain the underlying mechanism of such a preference. Our test incorporated different rodent species that dwell in different habitats and display different life and motor styles. We found that all the tested rodent species displayed a general preference to descend, with rodents from complex habitats being less affected by inclination compared with rodents from flatlands. Overall, when given the choice to ascend or descend, all the tested species displayed a preference to descend, perhaps as attraction to the ground (a behavior termed gravitaxis), where they usually have their burrows. Gravity polarizes the vertical axis and many animals can sense whether they are moving with gravity or against gravity. Gravitaxis, which is a movement in reference to a gradient, could therefore be a property involved in spatial behavior, a fundamental means of facilitating navigation, as manifested here in the rodents' general preference to descend rather than ascend. We directly tested whether, when given the choice to ascend or descend, rodents would favor traveling downwards or upwards. The test incorporated different rodent species that dwell in different habitats and display different life and motor styles. Testing was performed in a three-dimensional Y-maze in which the basis was horizontal and, by rotating it, one arm of the maze could be pointing upwards at a certain angle and the other arm pointed downwards at the same angle. All the tested species displayed a general preference for descent, with rodents from complex habitats being less affected by inclination compared with rodents from flatlands. Unlike laboratory rats, wild species traveled greater distances along the lower compared to the upper maze arm. All the rodents initially tended to travel the entire length of the inclined maze arms, but such complete trips decreased with the increase in inclination. When introduced into the maze from top or bottom, flatland dwellers traveled mainly in the entry arm. Overall, when given the choice to ascend or descend, all the tested species displayed a preference to descend, perhaps as attraction to the ground, where they usually have their burrows. [ABSTRACT FROM AUTHOR]

We directly tested whether, when given the choice to ascend or descend, rodents would favor traveling downwards or upwards. The test incorporated different rodent species that dwell in different habitats and display different life and motor styles. Testing was performed in a three-dimensional Y-maze in which the basis was horizontal and, by rotating it, one arm of the maze could be pointing upwards at a certain angle and the other arm pointed downwards at the same angle. All the tested species displayed a general preference for descent, with rodents from complex habitats being less affected by inclination compared with rodents from flatlands. Unlike laboratory rats, wild species traveled greater distances along the lower compared to the upper maze arm. All the rodents initially tended to travel the entire length of the inclined maze arms, but such complete trips decreased with the increase in inclination. When introduced into the maze from top or bottom, flatland dwellers traveled mainly in the entry arm. Overall, when given the choice to ascend or descend, all the tested species displayed a preference to descend, perhaps as attraction to the ground, where they usually have their burrows.

The karyotypes of four species of jirds of the genus Meriones Illiger, 1811 from Turkey and Iran (M. tristrami, M. persicus, M. vinogradovi and M. libycus) were studied using C-banding and AgNOR staining. The obtained basic karyotype characteristics of the studied species are in agreement with previously published data. Intra-specific variation in the number of autosomal arms was recorded in M. tristrami. Extensive variations were recorded in the number or localisation of active NOR sites between species and within species. The cytogenetic markers, such as the positive C-bands or NORs, seem to have only limited importance in inter-specific differentiation but they may be applied in studies of the relationships between geographic populations within species. [ABSTRACT FROM AUTHOR]

Abstract Oxidative damage is a potential physiological cost of thermoregulation during seasonal adjustments to air temperature (T a) in small mammals. Here, we hypothesized that T a affects serum thyroid hormone levels and these hormones can mediate the changes in metabolic rate and oxidative damage. Mongolian gerbils (Meriones unguiculatus) were acclimated at different T a s (5 °C, 23 °C and 37 °C) for 3 weeks. Serum tri-iodothyronine (T3) levels increased at 5 °C but decreased at 37 °C compared to the control (23 °C). Protein carbonyls increased in liver at 37 °C compared with control, however, lipid damage (malonaldehyde, MDA) in both serum and liver was unrelated to T a. After the effects of different T a s on thyroid hormone levels and oxidative damage markers were determined, we further investigate whether thyroid hormones mediated metabolic rate and oxidative damage. Another set of gerbils received 0.0036% L-thyroxin (hyperthyroid), 0.04% Methylimazol (hypothyroid) or water (control). Hypothyroid group showed a 34% reduction in resting metabolic rate (RMR) also 42% and 26% increases in MDA and liver protein carbonyl respectively, whereas hyperthyroid group had higher RMR, liver mass and superoxide dismutase (SOD) compared to control. Serum T3 or T3/T4 levels were correlated positively with RMR, liver mass, and SOD, but negatively with MDA and uncoupling protein 2 (UCP2). We concluded that high T a induced hypothyroidism, decreased RMR and increased oxidative damage, whereas low T a induced hyperthyroidism, increased RMR and unchanged oxidative damage. These data supported our hypothesis that thyroid hormones can be a cue to mediate metabolic rate and different aspects of oxidative and antioxidant activities at different T a s. Graphical abstract Unlabelled Image Highlights • Serum tri-iodothyronine level increased at 5 °C and decreased at 37 °C. • Hypothyroid led to a decrease in resting metabolic rate (RMR) but increases in malonaldehyde and liver protein carbonyl. • Hyperthyroid led to increases in RMR and superoxide dismutase but a decrease in uncoupling protein 2. • Thyroid hormones mediate RMR and oxidative, anti-oxidative balance. [ABSTRACT FROM AUTHOR]

River blindness and lymphatic filariasis are two filarial diseases that globally affect millions of people mostly in impoverished countries. Current mass drug administration programs rely on drugs that primarily target the microfilariae, which are released from adult female worms. The female worms can live for several years, releasing millions of microfilariae throughout the course of infection. Thus, to stop transmission of infection and shorten the time to elimination of these diseases, a safe and effective drug that kills the adult stage is needed. The benzimidazole anthelmintic flubendazole (FBZ) is 100% efficacious as a macrofilaricide in experimental filarial rodent models but it must be administered subcutaneously (SC) due to its low oral bioavailability. Studies were undertaken to assess the efficacy of a new oral amorphous solid dispersion (ASD) formulation of FBZ on Brugia pahangi infected jirds (Meriones unguiculatus) and compare it to a single or multiple doses of FBZ given subcutaneously. Results showed that worm burden was not significantly decreased in animals given oral doses of ASD FBZ (0.2–15 mg/kg). Regardless, doses as low as 1.5 mg/kg caused extensive ultrastructural damage to developing embryos and microfilariae (mf). SC injections of FBZ in suspension (10 mg/kg) given for 5 days however, eliminated all worms in all animals, and a single SC injection reduced worm burden by 63% compared to the control group. In summary, oral doses of ASD formulated FBZ did not significantly reduce total worm burden but longer treatments, extended takedown times or a second dosing regimen, may decrease female fecundity and the number of mf shed by female worms. [ABSTRACT FROM AUTHOR]

Flubendazole (FBZ) is highly efficacious against filarial nematodes after parenteral administration and presents a promising macrofilaricidal drug candidate for the elimination of onchocerciasis and other filariae. In the present study the efficacy of a newly developed bioavailable amorphous solid dispersion (ASD) oral formulation of FBZ was investigated in the Litomosoides sigmodontis jird model. FBZ was administered to chronically infected, microfilariae-positive jirds by single (40mg/kg), repeated (2, 6 or 15mg/kg for 5 or 10 days) oral (OR) doses or single subcutaneous (SC) injections (2 or 10mg/kg). Jirds treated with 5 SC injections at 10mg/kg served as positive controls, with untreated animals used as negative controls. After OR doses, FBZ is rapidly absorbed and cleared and the exposures increased dose proportionally. SC administered FBZ was slowly released from the injection site and plasma levels remained constant up to necropsy eight weeks after treatment end. Increasing single SC doses caused less than dose-proportional exposures. At necropsy, all animals receiving 1x or 5x 10mg/kg SC FBZ had cleared all adult worms and the 1x 2mg/kg SC treatment had reduced the adult worm burden by 98%. 10x 15mg/kg OR FBZ reduced the adult worm burden by 95%, whereas 1x 40mg/kg and 5x 15mg/kg OR reduced the worm burden by 85 and 84%, respectively. Microfilaremia was completely cleared at necropsy in all animals of the SC treatment regimens, while all oral FBZ treatment regimens reduced the microfilaremia by >90% in a dose and duration dependent manner. In accordance, embryograms from female worms revealed a FBZ dose and duration dependent inhibition of embryogenesis. Histological analysis of the remaining female adult worms showed that FBZ had damaged the body wall, intestine and most prominently the uterus and uterine content. Results of this study demonstrate that single and repeated SC injections and repeated oral administrations of FBZ have an excellent macrofilaricidal effect. [ABSTRACT FROM AUTHOR]

Study on Common Raven's diet is conducted in two regions in Algeria, region of Djelfa in the middle part of Algerian Highlands and region of Laghouat occupying a large part of Northern Algerian Sahara. Analysis of Corvus corax's regurgitation allowed us to count 2.726 individual-preys spread into 7 classes, 89 families, 26 orders and 232 preys-species. In term of F insects are the most ingested by Corvus corax. Rate of this class is of 81.1 % at level of El Guelta to reach 95.6 % in station of Sidi Mekhlouf. In term of biomass, Meriones shawii is the species the most profitable in weight in station of Sidi Mekhlouf (44.4 %), of Rocher des Pigeons (Pigeons Rock) (35.6 %) and even in station of El Guelta (14.3 %). However, in station of Dayet Zoujten, the highest biomass is presented by Gallus domesticus (42.1). This same observation is noted for species Gallus sp. (B % = 42.0 %) at level of El Mesrane. [ABSTRACT FROM AUTHOR]

The Mongolian squirrel is a murine rodent widely used as an experimental model and kept as a pet. With respect to the significance of the brachial plexus, we aimed to describe the origin and the nerves that constitute it, providing new information about the neuroanatomy of this species. Twenty adult animals were used, which were fixed in a 10% formaldehyde solution at the Applied Animal Morphophysiology Laboratory of the Brazilian Federal University of the Semi-Arid Region (UFERSA). The animals were medially incised with an opening of the thoracic cavity, and then bilateral dissection was carried out. Once the nerves were identified, cotton wool soaked with a 2% hydrogen peroxide solution was added for bleaching and better visualisation of structures. The gerbil brachial plexus derived from ventral roots of the fourth, fifth, sixth, seventh and eighth cervical nerves (C4-C8) and the first thoracic root (T1). The suprascapular nerve was formed from the nerve roots C4 and C5; the subscapular and cranial pectoral nerves from C5 and C6; the musculocutaneous and axillary nerves from C5, C6 and C7; and the caudal pectoral, radial, median, ulnar, thoracodorsal, lateral thoracic and long thoracic nerves from C7, C8 and T1. This resembles what is described in other rodents, such as the rat and capybara. The gerbil has a pre-fixed plexus conformation. [ABSTRACT FROM AUTHOR]

Jirds (Meriones) are a mostly desert-adapted genus of gerbils, with a wide geographic range, through which it encounters various climatic conditions, which may influence their morphology. In this study, we quantified cranial morphometric variation both within and among seven jird species (M. meridianus, M. hurrianae, M. crassus, M. tristrami, M. persicus, M. libycus and M. vinogradovi), based on a two-dimensional landmark-based geometric morphometric analysis of 972 specimens, covering their entire geographic distribution. The aforementioned analysis was used to compare sexual dimorphism in size and shape within each species, as well as the relationship between size and shape (i.e. allometry) for each species. Despite greatly overlapping in morphospace (when examined visually), statistical analysis indicates significant differences in both size and shape among the seven examined jird species. UPGMA and CVA both show two main species clusters. Deformation grids indicate that these two clusters differ mostly in the relative size of the tympanic bulla, along with differences in the extent of nasal elongation, and the broadness of the zygomatic arch. Allometric changes in shape were analyzed in all species that show an allometric relationship. Sexual dimorphism in shape and size was detected in only three of the seven jird species. A visual inspection of the data indicates high overlap in shape space, and that male skulls are significantly larger than female skulls. When specimens were divided by sex, we found significant allometry in six of the seven species (for both sexes). A factorial multivariate analysis of covariance (MANCOVA) indicated that even when taking size variation into account, the residual shape variation was also significantly different among the sexes of the examined species. The outcome of this study confirms the presence of cranial variation in the examined jirds, and that the patterns of sexual dimorphism and allometry vary considerably among jird species. [ABSTRACT FROM AUTHOR]

Meriones shawi (M. shawi) is a particular semi-desert rodent known by its resistance to long periods of thirst. The aim of the present investigation is to clarify the underlying mechanisms allowing M. shawi to resist to hard conditions of dehydration. For this reason we used two different approaches: i) a morphometric study, which consists in measuring the effect of dehydration on body and kidneys weights as well as the report kidney weight/body weight, ii) By immunohistochemistry, we proceed to study the effect of dehydration on the immunoreactivity of central vasopressin (AVP) and the kidney aquaporin-2 (AQP-2) which is a channel protein that allows water to permeate across cell membranes. Our results showed both a body mass decrease accompanied by a remarkable kidneys hypertrophy. The immunohistochemical study showed a significant increase of AQP-2 immunoreactivity in the medullar part of Meriones kidneys allowing probably to Meriones a great ability to water retention. Consistently, we demonstrate that the increased AQP-2 expression occurred together with an increase in vasopressin (AVP) expression in both hypothalamic supraoptic (SON) and paraventricular nucleus (PVN), which are a major hub in the osmotic control circuitry. These various changes seen either in body weight and kidneys or at the cellular level might be the basis of peripheral control of body water homeostasis, providing to M. shawi a strong resistance against chronic dehydration. [ABSTRACT FROM AUTHOR]

Homeric archaeology long dominated the study of early Greece, but new approaches have recently revolutionized the field. Drawing from these approaches, I offer a regional and diachronic analysis of Homeric stories about Crete, an assessment of the reception of these stories by the island's inhabitants throughout antiquity and an account of their impact on medieval to modern literature and art. I find that Cretan interest in Homer peaks in the Hellenistic period, but also argue for the much earlier familiarity of some Cretans with stories that underlie the Homeric epics. This argument relies on an analysis of the archaeological assemblage of a Knossian tomb of the 11th century BC, which includes a range of arms that is exceptional for both Aegean archaeology and the Homeric epics. In the epics, this equipment is carried by the Knossian hero Meriones, whose poetic persona can be traced back to the Late Bronze Age on philological and linguistic grounds. Based on this, and on current understandings of performance at death, I argue that the Knossian burial assemblage was staged to reference the persona of Meriones, therefore suggesting the familiarity of some Cretans with early stories that eventually filtered into the Homeric epics. [ABSTRACT FROM AUTHOR]

We have studied the quantitative and qualitative diet features of the rodent species in arid conditions of the Terek-Kuma Lowland in the Republic of Daghestan. We have determined the species composition, proportion, and diversity of food resources in the diets of the studied rodent species. The diet of rodents consists of various plants species. For example, the diet of Meriones tamariscinus consists of 29 plant species; M. meridianus, 40 species; Cricetulus migratorius, 26 species; Sylvaemus fulvipectus, 34 species; and Mus musculus, 30 species. The share of exclusively consumed plant species did not exceed 10% of the total amount of food. All pairs of rodent species have low or medium rate of diet overlapping. [ABSTRACT FROM AUTHOR]

Rodents of the Meriones shawii/grandis complex have been attested to in North Africa since the Middle Pleistocene and are abundant in archaeological sites. Today, they are widely spread and represent a major pest to local human populations. This complex, therefore, represents an accurate model for investigating the roles of climate change and human impact in shaping Quaternary faunal diversity and distribution. Many gray areas still exist regarding the systematics, ecology and geographical distribution of this complex, for both present and past populations. The purpose of this study is to compare modern genotyped and fossil Meriones specimens in order to 1) clarify the current systematics and distribution of the Meriones populations of the shawii/grandis complex, 2) document the taxonomic diversity in fossil Meriones from northwestern Africa, and 3) track their phenotypic and biogeographic evolution through time. To answer these questions we used geometric morphometrics on skulls (landmarks) and first upper molars (landmarks and sliding landmarks). We evidenced the existence of two morpho-groups within the M. shawii/grandis complex, with a clear geographic pattern ( M. grandis in Morocco vs. M. shawii in Algeria and Tunisia). Currently only one morpho-group, attributed to M. grandis , seems to exist in Morocco, with a small overlap with M. shawii in the most eastern part of the country. However, according to fossil data, M. shawii was also present in Atlantic Morocco during the Late Pleistocene. We have also highlighted the impact of Holocene climate change and habitat anthropization on this arid adapted group. During the Middle Holocene, a major climatic event (last interglacial optimum) seems to have induced a demographic collapse in Moroccan populations and the disappearance of the shawii clade from Morocco (except in the most eastern areas). Both species then re-expanded, benefitting from the increasing aridity and the new ecological niche driven by agriculture dispersal from the Neolithic onwards. [ABSTRACT FROM AUTHOR]

ThreeMerionesspecies inhabit Tunisia, namelyM. shawi,M. libycusandM. crassus, but little genetic data exist on these gerbils. We collectedMerionesfrom eight localities in Tunisia, and obtained mitochondrial (cytochromeb) and nuclear (IRBP) gene sequence data for 37 and 13 specimens, respectively, belonging to two species:M. shawiandM. libycus. We also optimised three microsatellite markers previously described inM. unguiculatusto obtain a finer analysis of their genetic diversity and geographic structure, given their wide distribution. Phylogenetic inferences of cytband IRBP data for these species, in the context of other gerbillin data, corroborate their taxonomic affinities reported by previous studies. High cytbhaplotype diversity was observed in both species (25 haplotypes in 29 and 27 sequences forM. shawiandM. libycus, respectively) with little geographical structure forM. shawibut three divergent groups inM. libycus. The average microsatellite diversity within each population was high (HO≥ 0.6,HE≥ 0.8) withM. libycuspopulations attaining the highest values. Population differentiation was moderate for several population pairs (Fst≥ 0.1), the highest being betweenM. shawipopulations. However, genetic distance among populations was not significantly correlated with geographic distance in eitherM. shawiorM. libycus. Our results contribute to a better characterisation of TunisianMerionesspecies, suggesting high geographic structure in mtDNA ofM. libycuspopulations within North Africa. [ABSTRACT FROM AUTHOR]

The Persian Jird, Meriones persicus, is distributed from Eastern Anatolia to Afghanistan and western Pakistan. Six subspecies were described based on skull features and coat colours, but the validity of these subspecies is uncertain, and no molecular work has ever been conducted on this species. Iran appears to be a key geographical region in which to revise the systematic and evolutionary history of this species, because five of the six subspecies are present in this country. To evaluate the phylogeographical history and taxonomy of this species in Iran, we used a combination of genetic (cytochrome b gene sequences of 70 specimens) and geometric morphometric (2D landmarks on the ventral side of skull of 258 specimens) analyses. We also used ecological niche modelling to make inferences about the evolutionary history of these lineages. Our molecular data highlight the existence of four genetic lineages, but they only partly correspond to the previously described subspecies. Our molecular and morphometric data confirm the validity of M. p. rossicus and show that it has a wider geographical range than previously thought. M. p. gurganensis and M. p. baptistae are genetically very close. The skull of M. p. gurganensis is morphologically distinguishable from other subspecies. The subspecies M. p. persicus and M. p. baptistae are genetically distinct, but morphologically close. Meriones p. ambrosius is genetically close to M. p. persicus, and additional analyses with more specimens are needed to validate its subspecific status. The genetic structure observed in Iran seems to fit the topography and biogeography of the country and emphasize the role of the Abarkooh, Central and Lut deserts as barriers to gene flow. All intraspecific divergent events within the Persian Jird occurred during the last 1.4 My, suggesting that climatic changes probably trigger diversification within this species. Our genetic and species niche modelling results suggest that potential refugial areas persisted during glacial periods for this species in north-western Zagros Mountains, north-eastern Alborz Mountains and Kohrud Mountains. [ABSTRACT FROM AUTHOR]

A parasitological survey of 107 jirds, belonging to two species, Meriones shawi and M. libycus, was carried out. Rodents were trapped in three separate desert regions of Tunisia: Bouhedma (in the centre), Dghoumes (in the southwest) and Sidi Toui (in the southeast). The survey revealed infection with nine helminth species – six cestodes: Raillietina sp., Meggittina numida, Meggittina gerbilli and Inermicapsifer madagascariensis, and two Taeniidae species: Taenia endothoracicus and Taenia sp.; and three nematodes: Gongylonema neoplasticum, Physaloptera sp. and Trichuris gerbilli. The overall prevalence of helminth infection was 68.22% (73/107); the highest rate was in M. shawi (80.82%, 59 cases), whereas it was 41.17% (14 cases) in M. libycus. The most frequent helminth was Raillietina sp. (53.27%) followed by Meggittina numida (21.5%). Merionesshawi showed the highest helminth diversity with eight parasite species, with synchronous infections of two, three and four species of helminths in one rodent, compared to M. libycus in which only two cestode species were found, without synchronous infection. Moreover, significant differences in the overall infection prevalence between sexes (60.27 and 39.73% for males and females, respectively) and age were detected; only one juvenile specimen of M. shawi was found infected. Prevalence depended also on habitat: the highest infection rate was in Bouhedma (80%), followed by Dghoumes (58.33%), and the lowest was in Sidi Toui (47.82%). [ABSTRACT FROM AUTHOR]

In order to improve the knowledge of terrestrial fauna in the Jabal Samhan Reserve - in southern Oman - several systematic surveys have been carried out in this region. Four specimens of the bushy-tailed jird, the gerbilline Sekeetamys calurus (Thos.) were collected from three localities. This is the first record for the species in Oman and also the first evidence that this jird is in a protected area along its known distribution range. This new record also enlarges the elevational limit known for the species, from 600 m to 1484 m. The animals obtained indicate that S. calurus has reproductive activity in July. [ABSTRACT FROM AUTHOR]

Palaeoenvironmental data and climatic reconstructions show that the Mediterranean ecoregion of North Africa underwent drastic ecological changes during the Pleistocene. Given its rich palaeontological record, North Africa is a pertinent region for documenting the role of climate change and human mediated-habitat changes on the demography and genetic structure of faunal species. In the present study, we collected data from this species in Morocco, Algeria, and Tunisia, and we combined molecular (mitochondrial and nuclear DNA sequences, microsatellites), fossil, palaeoenvironmental, and human context data to propose an explanation for the fluctuations of populations belonging to the Meriones shawii complex in the past. Genetic and fossil data both indicate a strong bottleneck in Moroccan populations at the Middle Holocene (last interglacial optimum) compared to the Late Pleistocene. Our mitochondrial DNA data suggest a diversification event within Morocco corresponding to the 130-125 kya interglacial optimum. Given that (1) major demographic changes in the M. shawii complex coincide with the interglacial optimums, and (2) the impact of human activities on the landscape and faunal communities was moderate during the Middle Holocene (beginnings of the Neolithic culture), our results demonstrate that climate, rather than anthropogenic influences, likely explains the M. shawii complex population decline in the Holocene. [ABSTRACT FROM AUTHOR]

Background: Rodents have important role as reservoirs of different parasites. The aim of this study was to determine helminth parasites of abundant rodents in Meshkin-Shahr, Ardabil Province northwest Iran. Methods: From April 2014 to March 2015; 205 rodents including 118 Meriones persicus, 63 Mus musculus and 24 Cricetulus migratorius were collected, using live traps. All rodents were dissected and their different tissues examined for infectivity with helminth parasites. Results: Overall, 74.2% of rodents were infected with helminth parasites. The rate of infectivity in M. persicus, M. musculus and C. migratorius was 82.2%, 61.9%, 66.7%, respectively. In general, among all 205 rodents, the species and infection rates of helminthes were as follows: Nematoda: Trichuris sp. (46.8%), Capillaria hepatica (18.1%), Syphacia frederici (14.2%), Aspicularis tetraptera (3.4%), Trichuris rhombomidis (2%), Heligmosomom sp. (2%), Streptopharagus kuntzi (0.5%), Spiruridae gen. sp. (0.5%); Cestoda: Hymenolepis nana fraterna (16.6%) Hymenolepis diminuta (7.3%) tetratiridium of Mesocestoides sp. (1%), Paranoplocephala sp. (0.5%), Cysticercus fasciolaris (0.5%), Taenia endothoracicus larva (0.5%), and Acanthocephala: Moniliformis moniliformis (18.5%). Conclusions: Variable species of helminthes circulate in the rodents of the study area. Presence of several zoonotic species highlights the potential risk of infections for public health. [ABSTRACT FROM AUTHOR]

We investigated interspecific interactions between two flea species ( Parapulex chephrenis and Xenopsylla ramesis) via evaluation of their feeding success (the size of a blood meal and time to death after a single blood meal) when they exploited rodent hosts [ Acomys cahirinus (a characteristic host of the former) or Meriones crassus (a characteristic host of the latter)] in single-species or mixed-species groups. We predicted that the negative interactions between the two fleas will result in smaller blood meals and shorter survival time in mixed- versus single-species infestations. We also predicted that the negative effect of mixed-species infestation on feeding performance would be less pronounced when fleas exploited their characteristic host rather than a non-characteristic host. When exploiting a characteristic host, P. chephrenis took larger blood meals in single- than in mixed-species groups, whereas the blood meal size in X. ramesis did not differ between treatments. When exploiting a non-characteristic host, no effect of group composition was found in either flea species. Survival time after a single blood meal was not affected by co-infestation or host species in either flea. Our results suggest context-dependence of the negative effect of co-infestation on feeding performance in fleas with the manifestation of this effect varying in dependence of flea and host species identities. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the clinical, surgical and diagnostic imaging findings in 11 cats and 3 dogs with suspected acute and chronic traumatic diaphragmatic hernia, and to compare the results of positive contrast cheliography (peritoneography) taken immediately and 5 min after the injection of contrast material. Thoracic and abdominal radiography, ultrasonography, and positive contrast cheliography of all animals were performed. Eight cases were considered as acute and six cases were considered chronic. The contrast images taken immediately after the injection of contrast material revealed the contrast material in the thoracic cavity in 8/8 acute trauma patients, but in none of the chronic cases. In 5/6 of these cases contrast material was seen in the thoracal cavity only in additional images taken after 5 min. One patient was diagnosed with FIP and excluded from the study. Twelve cases had complete resolution and one animal died during the early postoperative period. Our results suggest that positive contrast cheliography performed immediately after the injection of contrast material may not reveal chronic cases of diaphragmatic hernia and a second imaging (or imaging after 5 min) is indicated in order not to overlook chronic cases. [ABSTRACT FROM AUTHOR]

Variation in mammalian auditory bulla size has been linked to environmental conditions, and has even been claimed to provide a habitat-specific survival value. Enlarged bullae are typically shared among species adapted to living in arid habitats. Previous studies suggest that jirds also exhibit this adaptive enlargement of the bulla. However, such claims are based on the observation on a limited number of specimens, and thus they provide no quantitative support for this hypothesis. Therefore, we tested this hypothesis using a combination of geometric morphometrics and multivariate statistical techniques on a large sample of two jird species that exhibit a wide and partially overlapping geographical (and hence climatic) range, i.e., Meriones crassus (Sundevall, 1842) and M. libycus (Lichtenstein, 1823). A total of 485 intact skulls of populations originating from Africa to the eastern Iranian Plateau were analysed. The covariation between auditory bulla shape and several geoclimatic variables was explored using the two-block partial least-squares method. To some degree, the results seem to support the hypothesis that morphological variation in the auditory bulla is, indeed, correlated with geoclimatic variation. However, this finding cannot be generalised at several levels, hence refuting the hypothesis of convergent correlations between geoclimatic conditions and bulla morphology. Species-specific differences were found at different levels, suggesting that if local responses are present, they may reflect interactions with phylogenetic constraints. [ABSTRACT FROM AUTHOR]

Sound localization critically depends on detection of differences in arrival time of sounds at the two ears (acoustic delay). The fundamental mechanisms are debated, but all proposals include a process of coincidence detection and a separate source of internal delay that offsets the acoustic delay and determines neural tuning. We used in vivo patch-clamp recordings of binaural neurons in the Mongolian gerbil and pharmacological manipulations to directly compare neuronal input to output and to separate excitation from inhibition. Our results cannot be accounted for by existing models and reveal that coincidence detection is not an instantaneous process, but is instead shaped by the interaction of intrinsic conductances with preceding synaptic activity. This interaction generates an internal delay as an intrinsic part of the process of coincidence detection. The multiplication and time-shifting stages thought to extract synchronous activity in many brain areas can therefore be combined in a single operation. [ABSTRACT FROM AUTHOR]

Eighteen jirds were equally distributed in two treated and one control groups. The commercial products to the fenbendazole base (10mg) and the association of febantel (1.5mg), pirantel (1.44mg) and praziquantel (0.5mg) were orally administred in the concentration of 0.1ml in each group. The effectiveness of febendazole against oxiurids was 81.8%, 65.0 and 38.7% and for the association of febantel, pirantel and praziquantel was 72.7%, 73.8% and 51.0% on days 7, 14 and 21, respectively. Three applications of that dose of the tested medications, within intervals of 10 days, associated to hygiene, are recommended.

The article discusses the problem concerning the increasing diversity of the Meriones libycus or also known as the Libyan jird. Topics covered include the prevalence of the subspecies of the Libyan jird in the Mongolian plateau and in Morocco as well as the examination of the genetic diversity of the jird which could be found in Tunisia and China. Also mentioned is the genetic differences between the samples of Meriones libycus from China and those from Saudi Arabia.

Meriones shawi is an ubiquitous and endemic rodent in northern African. This species is considered as an economically important pest because it often damages crops. Moreover, the gerbillines are known to function as reservoirs for a variety of serious human epidemic diseases. Ten polymorphic microsatellite loci were identified using 454 GS-FLX Titanium pyrosequencing and a multiplex PCR assay was developed. The utility of these markers was evaluated in 30 individuals from three different Moroccan populations. Number of alleles per locus ranged from 2 to 7, with observed and expected heterozygosities ranging from 0.033 to 0.967 and from 0.033 to 0.729, respectively. Departures from Hardy-Weinberg equilibrium were observed at two loci. These markers will be useful resources for future population genetics studies for this rodent and pest-borne disease management. [ABSTRACT FROM AUTHOR]

ALT-2, a novel antigen belonging to the chromadorea ALT-2 family of the filarial nematode is proved to clear filarial parasites in Jirds. In order to increase the protection efficacy by stimulating the cell mediated immunity, MPLA a detoxified derivative of LPS known to induce the cellular response, was used in this study as an adjuvant on mice models. ALT-2+MPLA formulation elicited a high titer of total IgG antibody, with profoundly increased levels of IgG2b. Reduced splenocyte proliferation was observed in immunized group when compared to control groups which could be attributed to many in vivo factors. The levels of IFN-γ were high in unstimulated MPLA group compared to ALT-2 stimulated MPLA group, suggesting that the ALT-2 antigen suppressed the IFN-γ levels. A high level of IL-10 was induced by the ALT-2+MPLA formulation, which inhibited the production of Th2 cytokines (IL-4, IL-5) and also reduced the Th1 cytokine (IFN-γ, IL-2) levels which are not in vogue with the classical MPLA adjuvant formulation. We propose a mechanism for this immunomodulation which involves a diminished expression of TLR-4, by which the filarial parasites have evolved to evade host immune mechanism. [ABSTRACT FROM AUTHOR]

Rodents affect soil microbial communities by burrow architecture, diet composition, and foraging behavior. We examined the effect of desert rodents on nitrogen-fixing bacteria (NFB) communities by identifying bacteria colony-forming units (CFU) and measuring nitrogen fixation rates (ARA), denitrification (DA), and CO emission in soil from burrows of three gerbil species differing in diets. Psammomys obesus is folivorous, Meriones crassus is omnivorous, consuming green vegetation and seeds, and Dipodillus dasyurus is predominantly granivorous. We also identified NFB in the digestive tract of each rodent species and in Atriplex halimus and Anabasis articulata, dominant plants at the study site. ARA rates of soil from burrows of the rodent species were similar, and substantially lower than control soil, but rates of DA and CO emission differed significantly among burrows. Highest rates of DA and CO emission were measured in D. dasyurus burrows and lowest in P. obesus. CFU differed among bacteria isolates, which reflected dietary selection. Strains of cellulolytic representatives of the family Myxococcaceae and the genus Cytophaga dominated burrows of P. obesus, while enteric Bacteroides dominated burrows of D. dasyurus. Burrows of M. crassus contained both cellulolytic and enteric bacteria. Using discriminant function analysis, differences were revealed among burrow soils of all rodent species and control soil, and the two axes accounted for 91 % of the variance in bacterial occurrences. Differences in digestive tract bacterial occurrences were found among these rodent species. Bacterial colonies in P. obesus and M. crassus burrows were related to bacteria of A. articulata, the main plant consumed by both species. In contrast, bacteria colonies in the burrow soil of D. dasyurus were related to bacteria in its digestive tract. We concluded that gerbils play an important role as ecosystem engineers within their burrow environment and affect the microbial complex of the nitrogen-fixing organisms in soils. [ABSTRACT FROM AUTHOR]

Rodent pest population outbreaks occur frequently in grassland ecosystems in northern China. The Mongolian gerbil ( Meriones unguiculatus) is a dominant pest rodent which is distributed across the semi-desert grasslands of Inner Mongolia, China. In 2009, we studied the contraceptive effect of levonorgestrel-quinestrol (EP-1), concentration 50 ppm, on a wild Mongolian gerbil population. The one-off contraceptive treatment was compared with a control group using a semi-monthly live trapping method in the Ordos Semi-desert Grassland Region of Inner Mongolia. The results show that juveniles were not recruited in spring in the treatment group. Ratios of juveniles in the control and treatment groups showed significant semi-monthly differences from spring to summer (one-way ANOVA, F2, 14= 7.53, P < 0.05). Between both groups, annual fluctuations of juvenile and total population densities were significantly different respectively ( F2, 14= 4.64, P < 0.05; F2, 18= 7.72, P < 0.05). The contraceptive EP-1 delayed the normal reproductive pattern of Mongolian gerbil populations. This suppressed birth rates of gerbil populations, reduced their densities, and changed their age structures. The period of EP-1 baiting should be extended but it could be an ideal method for controlling Mongolian gerbil populations during each breeding season. [ABSTRACT FROM AUTHOR]

Jirds (genus Meriones) comprise a group of rodents, of which the biodiversity is still poorly known. Reason for this is that several species of similar morphologies are known to occur sympatrically. In the north-west of Iran, four such species occur: Meriones tristrami, Meriones persicus, Meriones vinogradovi and Meriones libycus, prone to several issues of taxonomical ambiguity. A proper characterization of morphological distinctiveness between these species, in relation to the variation within species, could provide the required information for species diagnosis and identification. As some cranial characters of M. tristrami, M. persicus and M. vinogradovi are quite similar, demarcations of species-specific phenotypic variation have proven to be difficult. To tackle this problem, this study involves a geometric morphometric analysis of skull shape and size, incorporating a large representative sample of these four species, originating from most parts of their natural distribution range (especially for M. tristrami). It is first tested whether M. tristrami can be distinguished from the other sympatric species, and if so, to what degree the species shows a geoclimatic pattern in its skull shape and size when comparing different populations. The shape and size analyses show that M. libycus can be distinguished because of its largest skull and the relatively largest tympanic bulla, and that M. tristrami can be distinguished from the other species. At an intraspecific level in M. tristrami, the Iranian groups (Qazvin and west Iran) do not differ in shape among them, but do so in skull size. They could, however, be distinguished in skull shape from the non-Iranian populations included (Turkey and Jordan). To what degree this continuous data can now be translated into discrete and diagnostic features, useful for taxonomic purposes, remains to be studied. [ABSTRACT FROM AUTHOR]

Abstract: The animal–environment interaction is complex, and the ability to temporally organise locomotor activity provides adaptive and survival advantages. We investigated daily and circadian locomotor activity patterns of two jird species from Arabia occurring in dramatically different environments to determine the environmental effect on activity. The King jird occurs in mountainous regions of Azir where climatic conditions are cool and wet, while the Libyan jird inhabits low-lying hot sandy deserts where temperatures exceed 45 °C during summer. Six King jirds and nine Libyan jirds were subjected to a 12L:12D light cycle, a period of constant darkness (DD) and an inversed 12D:12L light cycle. Five of six King jirds and all Libyan jirds showed entrainment of their activity to the light cycles, most animals exhibited nocturnal activity. All entraining jirds showed circadian rhythmicity, with the periods of the rhythms very close to 24 h. Entraining jirds inversed their activity patterns when the light cycle was inversed. The two jird species displayed comparable amounts of nocturnal activity in all light cycles presented. The King jird showed larger intraspecific variability than the Libyan jird, which may reflect more plasticity in its circadian clock, allowing it to adapt quicker to environmental changes. [Copyright &y& Elsevier]

Population estimates, often difficult to acquire, warrantee the use of an index as an economical substitute for rapid assessments of populations. We estimated population size of the little known social, semi-fossorial Indian desert jird ( Meriones hurrianae) in Kachchh, Gujarat, India under closed population capture-mark-recapture (CMR) framework to calibrate a burrow count index for the species. A total of 147 individuals were trapped in 16 colonies using baited Sherman traps and the number of burrow entrances at each colony was recorded. Data from colonies with low number of captures were pooled to estimate capture probability using Huggins heterogeneity models with gender, site, body weight and age category as covariates in Program MARK. Colony sizes ranged from 2 to 46 individuals. The number of burrow entrances was calibrated against CMR-based population estimates using least squares regression ( n = 16, adjusted R = 0.96, t = 18.18, P < 0.001). The index was further validated using Jackknife (JK) analysis where JK-predicted population estimates strongly correlated with CMR estimates ( r = 0.96, P < 0.001). In habitats and climatic conditions similar to Kachchh and within the range of colony sizes sampled, our calibrated index can be a valuable and effective tool for large scale surveys of the desert jird, which occupies a keystone trophic level in the semi-arid ecosystem. [ABSTRACT FROM AUTHOR]

A reliable disease model mimicking Enterovirus 71 (EV71) infection in humans is essential for understanding pathogenesis and for developing a safe and effective vaccine. Commonly used rodent models including mouse or rat models are not suitable for vaccine evaluation because the rodents are resistant to EV71 infection after they reach the age of 6 days. In this study, 21-day-old gerbils inoculated intraperitoneally (IP) with a non mouse-adapted EV71 strain developed neurological lesion-related signs including hind limb paralysis, slowness, ataxia and lethargy similar to those of central nervous system (CNS) infection of EV71 in humans. The infected gerbils eventually died of the neurological lesions and EV71 could be isolated from lung, liver, spleen, kidney, heart, spinal cord, brain cortex, brainstem and skeletal muscle. Significantly high virus replication was detected in spinal cord, brainstem and skeletal muscle by cellular analysis, real-time quantitative PCR (RT-PCR) and immunohistochemical staining. Histopathologic changes such as neuronal degeneration, neuronal loss and neuronophagia were observed in spinal cord, brain cortex, brainstem, and skeletal muscle along with necrotizing myositis and splenic atrophy. Gerbils that received two doses of inactive whole-virus vaccine showed no EV71-specific symptoms after challenged with EV71. In contrast, gerbils that received mock vaccination died of EV71-induced neuropathology after challenged with EV71. The result indicates that gerbils can serve as a reliable disease model for evaluating safety and efficacy of EV71 vaccine. [ABSTRACT FROM AUTHOR]

Abstract: In the present work we determined effects of a sub-chronic exposure to cadmium on some parameters of calcium and iodine metabolisms in Meriones shawi, a desert rodent species occupying the arid steppes of Tunisia and other countries. Fourteen jirds of both sex were equally divided into a control group receiving diet without cadmium and a treated group receiving cadmium in the diet during 30, 45, 60 and 90 days. At the end of each period, 5 jirds from each group were sacrificed. In cadmium-treated group, cadmium accumulation and total metallothioneins synthesis in the liver and kidneys were high and dependant on the duration of treatment. Cadmium caused significant modifications in the body weight and in the relative weights of the liver, femur and thyroids, in parallel to a decrease in calcium content in serum and in femur. Cadmium also decreased iodine content in serum and in the thyroids. Several impairments were dependant on the duration of exposure and were more pronounced at the end of the experiment. In conclusion, a sub-chronic exposure to cadmium induces perturbations in calcium and iodine metabolisms in Meriones shawi. However, effects on calcium seem to be more evident. We can conclude also that Meriones shawi is an indicator of cadmium presence in arid environments. [Copyright &y& Elsevier]

Background: The trehalose metabolic enzymes have been considered as potential targets for drug or vaccine in several organisms such as Mycobacterium, plant nematodes, insects and fungi due to crucial role of sugar trehalose in embryogenesis, glucose uptake and protection from stress. Trehalose-6-phosphate phosphatase (TPP) is one of the enzymes of trehalose biosynthesis that has not been reported in mammals. Silencing of tpp gene in Caenorhabditis elegans revealed an indispensable functional role of TPP in nematodes. Methodology and Principal Findings: In the present study, functional role of B. malayi tpp gene was investigated by siRNA mediated silencing which further validated this enzyme to be a putative antifilarial drug target. The silencing of tpp gene in adult female B. malayi brought about severe phenotypic deformities in the intrauterine stages such as distortion and embryonic development arrest. The motility of the parasites was significantly reduced and the microfilarial production as well as their in vitro release from the female worms was also drastically abridged. A majority of the microfilariae released in to the culture medium were found dead. B. malayi infective larvae which underwent tpp gene silencing showed 84.9% reduced adult worm establishment after inoculation into the peritoneal cavity of naïve jirds. Conclusions/Significance: The present findings suggest that B. malayi TPP plays an important role in the female worm embryogenesis, infectivity of the larvae and parasite viability. TPP enzyme of B. malayi therefore has the potential to be exploited as an antifilarial drug target. [ABSTRACT FROM AUTHOR]

Abstract: Dehydration is a powerful stimulus causing disequilibrium in homeostasis of water and electrolytes resulting from depletion in total body water. Most studies have focused on domestic and laboratory animals; however, the study of desert animals allows improved understanding about water balance and resistance to dehydration and associated behavioral changes, including those related to voluntary movements. Meriones shawi (Shaw''s Jird) is a desert rodent characterized by its resistance to long periods of thirst that can extend for several months. In the present study, M. shawi were subjected to water deprivation for 1month. We used tyrosine hydroxylase immunohistochemistry (TH: the key enzyme of catecholamine biosynthesis) to evaluate the effects of prolonged dehydration on the dopaminergic system in both substancia nigra pars compacta and ventral tegmental area (SNpc and VTA), which are the main sources of dopamine input to several brain areas; the immunolabelling was performed also in both the medial forebrain bundle and the caudate putamen (striatum). In addition, the open-field test was used to evaluate the effect of dehydration on locomotor activity in M. shawi. The results showed an increase in TH immunolabelling in both SNpc and VTA following 1month of dehydration compared to control levels. The same results were obtained with fibers in both MFB and striatum. This augmentation of TH immunoreactivity was accompanied by noticeable changes in locomotor activity behavior of Meriones, the recording test shows the hyperactivity of animals which is probably caused by dehydration. Overall, the results indicate that dehydration is able to increase dopaminergic neurotransmission, which might be involved in generating hyperactivity in this desert animal. [Copyright &y& Elsevier]

An accurate estimation of tympanic membrane stiffness is important for realistic modelling of middle ear mechanics. Tympanic membrane stiffness has been investigated extensively under either quasi-static or dynamic loading conditions. It is known that biological tissues are sensitive to strain rate. Therefore, in this work, the mechanical behaviour of the tympanic membrane was studied under both quasi-static and dynamic loading conditions. Experiments were performed on the pars tensa of four gerbil tympanic membranes. A custom-built indentation apparatus was used to perform in situ tissue indentations and testing was done applying both quasi-static and dynamic sinusoidal indentations up to 8.2 Hz. The unloaded shape of the tympanic membrane was measured and used to create specimen-specific finite element models to simulate the experiments. The frequency dependent Young's modulus of each specimen was then estimated by an inverse analysis in which the error between experimental and simulated indentation data was optimised for each indentation frequency separately. Using an 8 μm central region thickness, we found Young's moduli between 71 and 106 MPa ( n = 4) at 0.2 Hz indentation frequency. A standard linear viscoelastic model and a viscoelastic model with a continuous relaxation spectrum were used to derive a complex modulus in the frequency domain. Due to experimental limitations, the indentation frequency upper limit was 8.2 Hz. The average relative modulus increase in this domain was 14% and the increase was the strongest below 6 Hz. [ABSTRACT FROM AUTHOR]

The existence of cryptic species in the midday jird ( Meriones meridianus) has been suggested in literature, although based on little empirical data to support this hypothesis. In this study, a two-dimensional landmark-based geometric morphometric approach was used to investigate whether patterns in intraspecific variation in skull shape and size exist, using 110 skull specimens from more than 20 different localities along the distribution range of M. meridianus. This is the first study of morphological differences on such a big sample size and geographical range, and it tries to find whether skull shape variation in this species is best described as being clinal or rather reflecting cryptic diversity. The latter seems to be the case, as a dimorphic skull phenotype was found, reflecting a geographic disparity between the Middle East and the Far East specimens both in shape and in size. Distinct cranial differences were found in the overall cranial size and, also at the level of the inflation of the bulla, the elongation of the nasal, the length of the teeth row and the incisive foramen, as well as the distance in between the latter two. It thus seems that M. meridianus from Middle East is morphologically distinct from that of the Far East. Furthermore, our results also demonstrate that clinal variation could explain variation within Middle East populations, whereas a more heterogenous pattern is found for those of the Far East. The hypothesis that the observed phenotypic variation may reflect cryptic species is discussed, with the recommendation for a thorough taxonomical revision of the genus in the region. [ABSTRACT FROM AUTHOR]

In this study filarial recombinant protein or DNA vaccine constructs encoding BmALT-2 and BmVAH as single or as cocktail antigens were evaluated. Male jirds were immunized intramuscularly with DNA vaccine constructs or were immunized intraperitoneally with protein vaccine. The single and bicistronic DNA constructs induced substantial interferon-γ responses in spleen cells; antigen-specific responses were higher following immunization with the bicistronic cocktail construct and evoked a significant protective response of 57% in jirds challenged with Brugia malayi that was similar in the antibody-dependent cellular cytotoxicity (ADCC) assay and micropore chamber experiment. The cocktail protein vaccines induced a mixture of IgG2a (Th1) and IgG1 (Th2) responses with 80% protective response when challenged with B. malayi infective larvae. However, the single protein vaccine rALT-2 induced Th2 (IgG1/IgG3) with a 70% protective response and rVAH induced Th1 (IgG2a) with a lower proliferative response with 60% protection following challenge with B. malayi infective larvae. These results suggest that filarial cocktail protein vaccines are able to elicit substantial immune and protective responses when compared with single antigen vaccination in suitably vaccinated jirds. [ABSTRACT FROM AUTHOR]

In Tunisia, it was reported that Meriones shawi, a desert rodent, was contaminated by heavy metals around several industrial sites. In the present study, the effects of cadmium (Cd) on water metabolism regulation was studied in adult male Meriones shawi that received contaminated diet with cadmium chloride (CdCl2) for 8 days at (1 g Cd/1 L H2O/1.5 kg of granule flour). Expression of arginine-vasopressin (AVP), a crucial hormone for water regulation, was studied by immunohistochemistry in the hypothalamic supraoptic nucleus and paraventricular nucleus. Inspite of variations in water intake, Meriones shawi successfully maintained a balance between water influx and efflux. Cd treatment did not modify water flux rates. Total body water volume remained constant during the treatment in all groups studied. In contrast to what is known in laboratory rodents, water restriction induced an increase in expression of AVP in both supraoptic nucleus and paraventricular nucleus after eight days and two weeks of the experiment, respectively. A similar effect was also observed by treating Meriones with Cd. However, expression of AVP immunoreactivity from deprived water animals in the presence of Cd was markedly and significantly lower than in the absence of Cd. We conclude that Cd exposure modifies the vasopressinergic neuronal system and provides information regarding the neurotoxicity risks that this element presents for mammals and human populations exposed to even low amounts of Cd, without directly affecting water metabolism. Suitability of Meriones shawi as an accumulation bioindicator for Cd was also confirmed in this study. [ABSTRACT FROM AUTHOR]

Abstract: Supraoptic (SON) and paraventricular (PVN) nuclei are part of the hypothalamic–neurohypophysial system, they constitute the main source for vasopressin and they represent also obvious examples of activity-dependent neuroglial plasticity. Certain physiological conditions such as dehydration are accompanied by a structural remodeling of the neurons, their synaptic inputs and their surrounding glia. In the present work, an adult Meriones shawi (a rodent adapted to desert life) is used as an animal model. Using GFAP and vasopressin expressions as indicators successively of astrocytes and neuronal activations, the effect of a prolonged episode of water deprivation on the SON and PVN, hypothalamus nuclei were examined. We studied the immunoreactivity of GFAP and vasopressin in various hydration states (total deprivation of drinking water for 1 and 2months compared to hydrated animals). Prolonged dehydration produces an important decrease of GFAP immunoreactivity in both SON and PVN after 1 and 2months of water restriction. This decrease is accompanied by increased vasopressin immunoreactivity following the same periods of water deprivation. These findings may explain a real communication between vasopressin neurons and their surrounding astrocytes, thus the retraction of astrocytes and their processes is accompanied by an enhancement of vasopressin neuron density and their projecting fibers in response to this osmotic stress situation. Furthermore, these data could open further investigations concerning the possible involvement of the communication between astrocytes and vasopressin neurons in both PVN and SON in the regulation of Meriones hydrous balance and resistance to dehydration. [Copyright &y& Elsevier]

The article presents a study focusing on how transplantation of human neural stem or progenitor cells overexpressing galectin-1 improves functional recovery from focal brain ischemia in the mongolian gerbil. The findings of the study suggest the use of hGal1 in combination with transplantation of hNSPCs in the treatment of brain ischemia. It states that hNSPCs can generate all principle cell types such as neurons, astrocytes and oligodendrocytes in the brain and thus have great therapeutic potential in severe neurological diseases. The study offers an alternative method to apply hGal1 in the treatment of brain ischemia with transplantation of hNSPCs such as nestin-expressing hair follicle stem cells.

In order to uncover processes in the acquisition of spatial representation, we tested voles, jirds, and mice in a dark grid maze-a relatively homogenous environment comprising 16 identical equispaced crossroads and similar choice of paths at each crossroad. The three species initially displayed a tendency to retrace sections of their recently traversed path, perhaps indicating exploration and learning of an unfamiliar environment by virtue of repetition. All three species displayed the same decision making at crossroads. They had an equal tendency to progress forward, turn sideways, or turn back to retrace their path upon the first arrival at each crossroad. Over repeated visits to the same crossroad, however, progressing forward increased along with a decrease in turning back, but there was no change in the incidence of turning sideways. It is suggested that progressing forward is easier than making turns, since the latter oblige the navigator to remember the location of turning in order to retrace or integrate the path and remain oriented. The incidence of turning sideways, in being more difficult than forward progression and retracing, yet necessary in a restricted maze space, did not change over repeated visits to crossroads. Altogether, decision making at a crossroad may be described as going straight ahead for simplicity, retracing a path to memorize it, or turning sideways at a constant rate. The present tests in the grid maze illustrate how tangible entities (crossroads, paths) are integrated during the early phase of acquiring an abstract representation (map) of the maze. [ABSTRACT FROM AUTHOR]

Background: In order to verify the infectivity of rodents with endoparasites in Germi (Dashte-Mogan, Ardabil Province) the current study was undertaken. Methods: Using live traps, 177 rodents were trapped during 2005-2007. In field laboratory, all rodents were bled prior to autopsy, frozen at -20°C, and shipped to the School of Public Health, Tehran University of Medical Sciences, Iran. In parasitological laboratory, every rodent was dissected and its different organs were examined for the presence of any parasite. Blood thick and thin smears as well as impression smears of liver and spleen were stained with Geimsa and examined microscopically. Results: Two species of rodents were trapped; Meriones persicus (90.4%) and Microtus socialis (9.6%). The species of parasites found in M. persicus and their prevalences were as follows: Hymenolepis diminuta (38.8%), Hymenolepis nana (2.5%), Trichuris sp.(40.6), Mesocestoides larva (=tetrathyridium) (3.1%), Capillaria hepatica (6.9%), Moniliformis moniliformis (11.3%), Syphacia obvelata (2.5%), Taenia endothoracicus larva (0.6%), Physaloptera sp. (0.6%), Dentostomella translucida (0.6%), Heligmosomum mixtum (0.6%), Strobilocercus fasciolaris (0.6%),and Aspiculuris tetraptera (0.6%). The species of parasites found in M. socialis and their prevalences were as follows: H. diminuta (17.6%), Trichuris sp. (5.9%), Mesocestoides larva (5.9%), S. obvelata (11.8%), S. syphacia (11.8%), H. mixtum (17.6%), and Aspiculuris tetraptera (11.8%). There were no statistical differences between male and female for infectivity with parasites in either M. persicus or M. socialis. No blood or tissue protozoan parasite was found in any of the rodents examined. Conclusion: Among different species identified, some had zoonotic importance. Therefore, the potential health hazard of these species needs to be considered to prevent infectivity of humans. [ABSTRACT FROM AUTHOR]

The nitrogen-fixing activity, nitrogen (N) and carbon (C) contents, and the number of microorganisms in the forestomach, cecum, and colon were detected in two gerbil species, granivorous Meriones meridianus and M. tamariscinus, which consume a large amount of green parts of the plants. M. meridianus had higher levels of nitrogen-fixation activity in all investigated parts of the gastro-intestinal tract compared with M. tamariscinus. The highest levels were detected in the colon of M. meridianus. The C/N ratios in the forestomach of M. tamariscinus were higher than in M. meridianus, which is consistent with the greater role of the green parts of plants in its diet. A gradual increase in the nitrogen content from the forestomach to the colon of M. tamariscinus was noted. The amount of microorganisms in the forestomach and intestine of the studied gerbil species was similar. [ABSTRACT FROM AUTHOR]

It has become difficult in recent years to conduct the direct feeding of mosquitoes on animals because of ethical considerations related to animal experimentation. Thus, the artificial feeding of mosquitoes on blood meals is an important technique in studies on the oral infection of mosquitoes to agents. Since Rutledge et al. (1964) devised the artificial membrane-feeding technique, several artificial membrane-feeding methods have been developed to increase the feeding rates of mosquitoes on blood meals. The purpose of the present study is to develop a simple and convenient device for the artificial feeding of mosquitoes.We designed a device using Kimwipe®, a coverglass, the lid of a plastic dish and a 50 ml Erlenmeyer flask. The efficacy was assessed by the infection rate of mosquitoes to Brugia pahangi microfilariae (MF) derived from the peritoneal cavity of Mongolian jirds. Immediately after the feeding of mosquitoes on MF by the new device, the MF infection rate of mosquitoes was 50 - 81%. On day 14 post-feeding, 51 - 94% of mosquitoes harbored third-stage infective larvae. The components needed to construct the device for artificial feeding of mosquitoes are generally available in laboratories. Furthermore, no elaborate modification of materials is necessary in making the feeding device. Therefore, this simple and convenient artificial feeding device promises to be applicable for experimental infection of mosquitoes not only with B. pahangi MF but also with other agents such as malaria and viruses. [ABSTRACT FROM AUTHOR]

The distribution of nucleolar organizer regions (NORs) in Cricetulus migratorius and Meriones tristrami from Central Anatolia was determined. In the karyotype of Cricetulus migratorius the diploid number, fundamental number, and fundamental autosomal number are 22, 44, and 40, respectively. The diploid number, fundamental number, and fundamental autosomal number of Meriones tristrami are 72, 84, and 80, respectively. In Cricetulus migratorius, NORs occur in the telomeric regions of metacentric and subtelocentric autosome pairs. Furthermore, terminally located NORs in metacentric and acrocentric autosomes of Meriones tristrami are presented in this present paper. [ABSTRACT FROM AUTHOR]