Mesocricetus Brandti Research Articles

Hibernation Records on the Incisor Surface in the Turkish Hamster (Mesocricetus brandti) (Rodentia, Cricetidae)

The teeth of an adult female of the Turkish hamster (Mesocricetus brandti) after hibernation in semi-natural conditions were examined to reveal a relationship between the hibernation pattern on the incisor surface and the data of a temperature logger. The female spent the winter in a burrow prepared by herself inside a wintering cage from October 2018 till May 2019. A temperature logger was implanted to the animal intraperitoneally to record body temperature at 20-min intervals. Regular bouts of hypothermia started in mid-October. The longevity of each hypothermia bout increased whereas the minimum body temperature decreased and reached its lowest value in March. Later, the process proceeded backwards until the end of the heterothermia period. In the apical region of the incisor, daily increments were wide and well-distinguished which indicates that they had formed before the onset of the heterothermal period. In the basal region, closer to the growth zone, the increments were narrow and distinct, and their number corresponded in general to the number of normothermia episodes bouts. At the very base of the incisor as well as at its apical part, typical daily increments were revealed again. However, no correlation between the longevity of normothermia bouts and the width of increments was found. These data varied greatly from two other hamsters. In the Ciscaucasian hamster (Mesocricetus raddei) the number and character of increments comply with the number and duration of normothermia bouts, in the Common hamster (Cricetus cricetus), the “hibernation zone” was not recorded on the incisor surface. The Turkish hamster demonstrate an intermediate pattern, which we explain by quite different hibernation conditions of these species.

Investigation on Diet of Long-Eared Owl (Asio Otus) Inhabiting Fatih Natural Park (Turkey)

Pellet analyses were used to identify small mammal species in the diet of this owl species in order to reveal its ecological role. In this study, 706 pellets of Asio otus were collected from 3 different localities in Fatih Natural Park between February and March 2014. Pellets were dissolved by using 3% NaOH solution and then bones were dehydrated and identified. The aim of this study was to determine mammal composition in the diet of Asio otus inhabiting Fatih Natural Park of Yozgat Province, Turkey. Residues of bone from 1293 individuals/preys corresponding to 42377.41 g biomass in total were detected as the result of analysis. These individuals were identified to belonging to 12 mammal species ( Crocidura suaveolens , Suncus etruscus , Microtus hartingi/lydius , Microtus levis , Microtus sp., Cricetulus migratorius , Mesocricetus brandti , Apodemus sp., Apodemus sylvaticus , Apodemus whitherbyi , Mus macedonicus , and Meriones tristrami ) from 3 families and 8 genera. Microtus hartingi/lydius, which is known as agricultural pest, was dominant in the diet of Asio otus . When diversity of mammal species within the food composition was examined, Asio otus nesting in forest was found to primarily prefer agricultural and steppe areas, and was also found in woody and bushy areas. The use of Asio otus can be taken into consideration when dealing with rodent species known as agricultural pests.

The rodent fauna from the Neolithic human settlement of Tepecik-Çiftlik (Niğde, Turkey)

AbstractThe primary aim of this study was to establish for the very first time the results on the rodent fauna gathered from the ongoing Neolithic excavations at the Tepecik-Çiftlik site in southern Cappadocia (Niğde, Turkey). So far, the fauna being study is represented by species of arvicolines (Microtuscf.arvalisandArvicolacf.amphibius), murines (Muscf.musculus), sousliks (Spermophilus xanthoprymnus), hamsters (Mesocricetus brandti) and mole-rats (Spalax xanthodon), and their remains are described in detail. Paleoenvironmental assumption based on common preferences of the fauna elements indicates, at first sight, a rather dry steppe environment with sparse plant cover or perennial short grasses. On the other hand, the presence ofArvicolacf.amphibiuspoints out streams and marsh-like vegetation cover with bodies of water . The predation or burn marks observed on some specimens and the presence of subterraneous rodents raise questions concerning their taphonomy.

Nematodes of rodents of Armenia

This review summarizes known data on the species composition of nematodes in 24 species of rodents inhabiting the territory of Armenia (South of Lesser Caucasus). The studied rodents include members of some cosmopolitan species (Mus musculus, Rattus norvegicus, Rattus rattus), as well as endemic and narrow-areal species (Meriones vinogradovi, Spermophilus xanthoprymnus, Microtus schidlovskii, Mesocricetus brandti, Sciurus anomalus). The taxonomical identity of the nematode species reported by previous authors is discussed with regard to present knowledge about helminth fauna of rodents. Our review concludes that 34 nematode species are present in rodents in Armenia, five of which are identified for the first time in rodents from the territory of Armenia, and three of which (Trichinella spiralis, Trichostrongylus colubriformis, Trichostrongylus skrjabini) are able to parasitize humans.

Genetic characterization of the Turkish gray hamster (Cricetulus migratorius) based on mitochondrial cytochrome b and 12S rRNA sequences

Although genetic diversity and phylogenetic status of the gray hamster (Cricetulus migratorius) have been investigated from different regions in previous studies, genetic data on this species from Turkey are still lacking, since previous data have been based on a limited number of gray hamsters sampled across the Anatolian part of Turkey. The aim of this study was to determine the genetic diversity of the Anatolian population and to reveal the phylogenetic relationships among the Anatolian population and conspecific populations of the gray hamster. The complete and partial fragments of mitochondrial Cyt b and 12S rRNA from the 20 Turkish samples were amplified and sequenced. Ten 12S rRNA (901 bp) and 15 Cyt b (1140 bp) haplotypes found in this work were not previously reported. Based on Bayesian, Maximum Likelihood, Neighbour-Joining and Median-Joining network analyses by using mitochondrial data under the name Cricetulus, the results of phylogenetic and network analyses indicated that there was a deep separation among the distinct lineages within the genus Cricetulus. When considering the position of the Turkish haplotypes in median joining network, the Anatolian part of Turkey may have hosted a source population of the gray hamster for expansion to adjacent regions in the past period. Additionally, the Anatolian population of gray hamster had relatively high haplotype diversity and the present study propounded the importance of data obtained from the Anatolian population of gray hamster to reveal the phylogenetic relationships among conspecific populations of the gray hamster.

Genetic structure of the Turkish hamster (Mesocricetus brandti)

We examined the natural population structure of the Turkish hamster (Mesocricetus brandti) by analysing partial mitochondrial sequences of the control region and the cytochrome b gene. Evolutionary lineages were defined on haplotype clusters in genetic trees and a median-joining network. Most significant divergence events in M. brandti nested in the lower Pleistocene. Gene flow prevented spatial genetic differentiation among most populations contrasting previous ideas about potential subspeciation in Anatolia. None of the mitochondrial lineages showed significant signs of recent expansion indicating relatively stable ecological conditions during recent population history. Furthermore, we discussed aspects of the evolution of M. brandti and the genus Mesocricetus in the context of available fossils.

Contributions to the Knowledge of Mammals in Çorum Province, Turkey

A total of 42 mammal species were determined and new records reported for the first time in Corum Province, Turkey. Field studies were carried between 2009-2010 and 2015-2016. One species of hedgehog and shrew, four bat species, six rodent species, roe deer and three carnivore species were recorded for the first time. We also expanded the known distribution and confirmed the presence of four rodent species (Spermophilus xanthophyrmnus, Microtus dogramaci, Mesocricetus brandti and Meriones tristrami) in the province. In addition, some information related to the distribution and the habitat associated to some taxon were provided in the study. Keywords: Mammal fauna; Corum; Camera trap; Sherman trap DOI: 10.17350/HJSE19030000049 Full Text: Research Article

Specific features of the record of hibernation on the incisor surface in Allocricetulus hamsters

To evaluate how the course of irregular winter hibernation is recorded in the incisor teeth of Allocricetulus hamsters, an analysis was performed of the incisor surface in seven A. curtatus and two A. eversmanni hamsters and stained section of the incisors in one A. curtatus hamster. The animals were kept in cages at natural temperature and photoperiod. Five hamsters were implanted with a temperature data logger, and another five received tetracycline injections (5–20 days before death). In addition, the incisor surface was examined in eight A. curtatus and eight A. eversmanni hamsters trapped in the field. In hibernating hamsters, the duration of alternating periods of hypothermia (torpor bouts) and normothermia (arousals) and their ratio varied irregularly and randomly within and between individuals. Increments on the incisor surface were of two types: wide and poorly defined or narrow and distinct. The increments in hamsters trapped in the field were slightly more distinct than in experimental captive animals, and those in two hamsters that failed to hibernate were similarly wide and indistinct. In hibernating hamsters, wide increments proved to correspond to long periods of normothermia, while narrow increments were formed when torpor bouts alternated with short arousals. More distinct narrow increments formed when torpor bouts followed by short (no more than 1.5-days) arousals occurred in a series rather than singly. Although the number of narrow increments was approximately similar to that of short arousals, in was impossible to localize the record of each particular hypo/normothermia episode on the incisor surface. Dentin layers in stained preparations had no definite pattern and corresponded to these episodes no better than the increments on the incisor surface. In general, the narrow and distinct increments in a given Allocricetulus hamster is evidence that the animal did hibernate, and the number of such increments indicates the approximate minimum number of torpor bouts followed by arousals. The record of winter hibernation on the incisors of Allocricetulus hamsters has a pattern similar to that in Mesocricetus brandti (Batavia et al., 2013) but significantly differs from the pattern described in M. raddei (Klevezal et al., 2012).

Chromosomal Arrangements Based on Fundamental Number of Chromosomal Arms (FN) of Hybrid Individuals of Mesocricetus brandti

In this study, Mesocricetus brandti (Nehring, 1898) specimens collected from different area of Anatolia (Sebinkarahisar, Bolkar Mountain, Aksaray, Ardahan, Van) and Iran- Zanjan were examined. Chromosomal arrangements of these individuals were analyzed by using colchicine- hypotonic citrate karyotype technique. Diploid chromosome numbers of whole specimens were determined to be the same, being 2n=42; however fundamental number of chromosomal arms (FN) of these specimens had two forms; being FN=84 and FN=82. These two forms were mated in laboratory conditions and hybrid individuals (both male and female) obtained from interbreeding specimens of Zanjan (Iran) which has 84 FN and Bolkar Mountain (Nigde, Turkey) which has 82 FN. It is determined that, these hybrid individuals have 83 chromosomal arms (FN) and one of homologous chromosomes of the 20 th autosomal pair is acrosentric and the other is metacentric.

Laguna Negra Virus Infection Causes Hantavirus Pulmonary Syndrome in Turkish Hamsters (Mesocricetus brandti).

Laguna Negra virus (LNV) is a New World hantavirus associated with severe and often fatal cardiopulmonary disease in humans, known as hantavirus pulmonary syndrome (HPS). Five hamster species were evaluated for clinical and serologic responses following inoculation with 4 hantaviruses. Of the 5 hamster species, only Turkish hamsters infected with LNV demonstrated signs consistent with HPS and a fatality rate of 43%. Clinical manifestations in infected animals that succumbed to disease included severe and rapid onset of dyspnea, weight loss, leukopenia, and reduced thrombocyte numbers as compared to uninfected controls. Histopathologic examination revealed lung lesions that resemble the hallmarks of HPS in humans, including interstitial pneumonia and pulmonary edema, as well as generalized infection of endothelial cells and macrophages in major organ tissues. Histologic lesions corresponded to the presence of viral antigen in affected tissues. To date, there have been no small animal models available to study LNV infection and pathogenesis. The Turkish hamster model of LNV infection may be important in the study of LNV-induced HPS pathogenesis and development of disease treatment and prevention strategies.

Effects of Pinealectomy and Short Day Lengths on Reproduction and Neuronal RFRP-3, Kisspeptin, and GnRH in Female Turkish Hamsters.

Long days (LDs) stimulate and short days (SDs) inhibit reproduction in photoperiodic rodents by modifying nocturnal pineal melatonin secretion. In LD Turkish hamsters, unlike other rodents, pinealectomy induces reproductive quiescence comparable to that produced by SDs. We assessed whether SDs and pinealectomy induce similar or different patterns of kisspeptin and gonadotropin-inhibitory hormone (also known as RFamide-related peptide-3 [RFRP-3] in mammals) expression, important mediators of seasonal reproductive changes in other species. Brains were harvested from sham-operated female Turkish hamsters maintained in LDs and SDs and LD-pinealectomized (pinx) females, all housed in their respective photoperiods for 12 weeks. Uterine weights were substantially higher in LD-sham than in LD-pinx and SD-sham females. RFRP-3-immunoreactive(-ir) cells in the dorsomedial hypothalamic nucleus were greater in number and size in the reproductively competent LD-sham hamsters than in both reproductively suppressed SD-sham and LD-pinx hamsters. LD-sham hamsters had more kisspeptin-ir cells in the anteroventral periventricular nucleus than did LD-pinx hamsters. Reproductive quiescence, whether induced by short-day lengths or pinealectomy, was generally accompanied by comparable changes in RFRP-3 and kisspeptin, suggesting that long-duration melatonin signaling and withdrawal of melatonin by pinealectomy may act through the same neural substrates to induce gonadal quiescence.

The effects of day length, hibernation, and ambient temperature on incisor dentin in the Turkish hamster (Mesocricetus brandti)

Dentin is deposited on a circadian basis, and daily layers manifest as bands on the medial surfaces of rodent incisors. Hibernation alters dentin deposition, and a distinct hibernation mark has been described on incisor surfaces of several rodent species; the factors that influence the morphology of this mark are poorly understood. We tested the effects of day length, torpor expression, and ambient temperature on incisor surface morphology in Turkish hamsters housed in one of four conditions: long days (LDs) at 22°C, short days (SDs) at 22°C, SDs at 5°C, and SDs at 13°C. Body temperature was monitored continuously with implanted radio transmitters, and teeth examined postmortem. Teeth of SD hamsters had narrower, less distinct circadian increments than those of LD hamsters, but the width of ultradian increments was similar in both photoperiods. Hibernation at both 5 and 13°C was associated in most specimens with very narrow, sharply defined dentin increments and increased tooth heterogeneity. Hamsters in SDs at 5°C that did not hibernate lacked characteristic hibernation increments. At 5°C, but not 13°C, the number and cumulative width of hibernation increments were related to number and cumulative duration of periodic arousals. Our results suggest that incremental deposition of dentin in rodent incisors may be a useful trait for characterizing hibernation behavior in both evolutionary and historical contexts.

Interactions with heterospecific males do not affect how female Mesocricetus hamsters respond to conspecific males

Reproductive interference includes any interspecific interaction that reduces the fitness of one or both species involved. There are several types of reproductive interference, but they normally involve the direct cost of interacting or mating with heterospecifics. An indirect cost of interacting with heterospecific individuals is a consequent reduction in successful interactions with conspecifics. We tested the hypothesis that being aggressive towards a heterospecific individual will diminish sexual responses towards conspecifics in later encounters. We used two species of Mesocricetus hamsters (Syrian and Turkish hamsters), whose interspecific interactions have previously been determined. We exposed or both exposed and paired Syrian hamster females with a conspecific or a heterospecific male. Five minutes later, we paired all females with a conspecific male and measured the latency to lordosis, the duration of lordosis and any incidence of aggression. We found that (1) interactions with heterospecific males did not affect how females responded to conspecific males in later encounters and (2) previous pairing of female subjects with either conspecific or heterospecific males promoted a faster sexual response by females in subsequent interactions with conspecific males. Thus, aggressive interactions of Syrian hamster females with heterospecific males, contrary to our initial hypothesis, had a positive effect on subsequent interactions with conspecific males.

Hibernation patterns of Turkish hamsters: influence of sex and ambient temperature

Turkish hamsters (Mesocricetus brandti) are a model organism for studies of hibernation, yet a detailed account of their torpor characteristics has not been undertaken. This study employed continuous telemetric monitoring of body temperature (T(b)) in hibernating male and female Turkish hamsters at ambient temperatures (T(a)s) of 5 and 13 °C to precisely characterize torpor bout depth, duration, and frequency, as well as rates of entry into and arousal from torpor. Hamsters generated brief intervals of short (<12 h), shallow test bouts (T(b) > 20 °C), followed by deep torpor bouts lasting 4-6 days at T(a) = 5 °C and 2-3 days at T(a) = 13 °C. Females at T(a) = 5 °C had longer bouts than males, but maintained higher torpor T(b); there were no sex differences at T(a) = 13 °C. Neither body mass loss nor food intake differed between the two T(a)s. Hamsters entered torpor primarily during the scotophase (subjective night), but timing of arousals was highly variable. Hamsters at both T (a)s generated short, shallow torpor bouts between deep bouts, suggesting that this species may be capable of both hibernation and daily torpor.

Asymmetric learning to avoid heterospecific males in Mesocricetus hamsters

If a female mates with a male of a closely related species, her fitness is likely to decline. Consequently, females may develop behavioral mechanisms to avoid mating with heterospecific males. In some species, one such mechanism is for adult females to learn to discriminate against heterospecific males after exposure to such males. We have previously shown that adult, female Syrian hamsters (Mesocricetus auratus) learn to discriminate against male Turkish hamsters (Mesocricetus brandti) after exposure to a single heterospecific male during 8days across a wire-mesh barrier. Here we repeated that experiment but this time we exposed female Turkish hamsters to a male Syrian hamster for 8days and then measured sexual and aggressive behaviors towards that heterospecific male and towards a conspecific male. In contrast to female Syrian hamsters, female Turkish hamsters did not differ in their latency to go into lordosis or in any measure of aggression towards either type of male. Female Turkish hamsters spent less time in lordosis with the heterospecific male, but the percentage of trials in which females copulated with conspecific and heterospecific males did not differ. When comparing females from both species that had been exposed to a heterospecific male for 8days, female Syrian hamsters copulated less and were more aggressive towards the heterospecific male compared to the behavior of female Turkish hamsters. We discuss how this asymmetric response between females of the two species may be due to the much larger geographical range of Turkish hamsters compared to Syrian hamsters.

Nucleolar organizer regions in Mesocricetus brandti (Nehring, 1898) (Mammalia: Rodentia) from the Yozgat and Tokat provinces of Turkey

Mesocricetus brandti possesses a diploid chromosome number of 2n = 42, a fundamental number of NF = 82, and a fundamental number of autosomal arms of NFa = 78. The chromosome set consists of 17 meta-submetacentric pairs, 2 subtelocentric pairs, and 1 acrocentric pair. The X chromosome is large and metacentric while the Y is medium-sized and metacentric. The nucleolar organizer regions were located at the telomeric region of 7 biarmed autosomes and at the centromeric region of 1 acrocentric autosome.

Elimination of Short-Day Melatonin Signaling Accelerates Gonadal Recrudescence but Does Not Break Refractoriness in Male Turkish Hamsters

Long days stimulate and short days (SDs) inhibit the reproductive axis of photoperiodic rodents. In long-day Turkish hamsters, unlike most other rodents, elimination of pineal melatonin secretion by constant light or pinealectomy initiates a cycle of gonadal involution and recrudescence outwardly similar to that induced by short days. The present study assessed whether short days and constant light induce the seasonal reproductive cycle via common or different interval timing mechanisms. Male hamsters that had undergone gonadal involution in SDs for 8 or 14 weeks were treated with LL for 14 and 8 weeks, respectively. If SDs and LL act via independent mechanisms, then gonadal quiescence of SD-regressed males, which normally lasts 10 weeks, might be extended by LL treatment; alternatively, if SDs and LL act on the same timer, or the timer cannot be retriggered, then LL will not extend the duration of reproductive quiescence. Neither of these outcomes materialized. Instead, male hamsters exposed to LL while reproductively quiescent exhibited accelerated gonadal recrudescence. Extended LL treatment did not restore responsiveness to SDs in photorefractory hamsters. In Turkish hamsters, photoperiodic history determines whether constant light inhibits or stimulates the hypothalamic-pituitary-testicular axis.

Avoidance of interspecific mating in female Syrian hamsters is stronger toward familiar than toward unfamiliar heterospecific males

Adult Syrian hamster females (Mesocricetus auratus) learn to discriminate against familiar heterospecific males (Turkish hamster, M. brandti). We investigated whether females learn to avoid any heterospecific male after exposure to just one heterospecific male. We predicted that, after being exposed to one heterospecific male, a female would avoid mating not only with that familiar male but also with any unfamiliar heterospecific male. We exposed females to a heterospecific male across a wire-mesh barrier for 8 days and then paired the female with (a) that same heterospecific male or (b) an unfamiliar heterospecific male. Females exhibited lordosis faster and for a longer duration toward the unfamiliar than toward the familiar heterospecific male. However, females were similarly aggressive toward familiar and unfamiliar heterospecific males. Perhaps exposure to stimuli from several heterospecific males (a likely scenario in the wild) would result in females behaving similarly toward familiar and unfamiliar heterospecific males.

Some small mammal fossils of Üçağızlı Cave (Hatay, Turkey)

Small mammal assemblages of Üçağızlı Cave, 2 from the early Upper Paleolithic and 1 from the Epipaleolithic, spanning a period from 41 to 17 kya, are described. The remains are referred to as Chionomys nivalis, Microtus guentheri, Apodemus mystacinus, Apodemus flavicollis, Apodemus witherbyi, Mus macedonicus, Mesocricetus brandti, Glirulus sp., Crocidura sp., Pipistrellus cf. kuhlii, and Myotis sp. The rodent fauna of Üçağızlı suggests the dominance of open country and rocky ground with a woodland component. There does not seem to have been any essential environmental changes during the deposition of these layers. However, the poor sample of the Epipaleolithic hampers environmental conclusions. The rodent assemblages of Üçağızlı contain European, local, and Asiatic elements. All of the rodent taxa from Üçağızlı, except for Glirulus, are also known from the contemporaneous levels of Karain B and the extant fauna of the Hatay region. This shows that the rodent fauna of the eastern Mediterranean has not changed much since the Late Pleistocene.

Adult female hamsters require long and sustained exposures to heterospecific males to avoid interspecific mating

Interspecific mating normally decreases female fitness. In many species, females avoid heterospecific males innately or by imprinting on their parents. Alternatively, adult females could learn to discriminate against heterospecific males after exposure to such males. For example, Syrian hamster (Mesocricetus auratus) females learn to discriminate between conspecific males and Turkish hamster (M. brandti) males during adulthood by exposure to males of both species. Adult females not previously exposed to Turkish hamster males will mate similarly with conspecific and heterospecific males. However, in a previous study we showed that exposure to a heterospecific male and a conspecific male for 8 days led to mating avoidance and aggression towards the heterospecific male. Here we conducted two experiments to investigate how much exposure to the heterospecific male was required for females to avoid mating with the heterospecific male (Experiment 1) and how long that avoidance lasted in the absence of continuous exposure to heterospecific stimuli (Experiment 2). Fast and durable learning would indicate the evolution of an efficient avoidance response. In Experiment 1, females were exposed to a heterospecific male for 1, 4 h, 4 or 8 days and then paired with that male. We found more avoidance of interspecific mating after 4 or 8 days of exposure than after 1 or 4 h of exposure. In Experiment 2, females were exposed to a heterospecific male for 8 days and then paired with that male either 10 min later or 8 days later. We found that after an 8-day delay females were highly sexually receptive to the heterospecific male. Additionally, a comparison between the current experiments and a previous study indicates that female Syrian hamsters do not require concurrent exposure to a conspecific male and a heterospecific male to learn to avoid interspecific mating; exposure to a heterospecific male is sufficient.