The Experts below are selected from a list of 6357 Experts worldwide ranked by ideXlab platform
Rolf Gattermann - One of the best experts on this subject based on the ideXlab platform.
-
Microsatellites for diversity studies in the golden hamster (Mesocricetus auratus)
Molecular Ecology Notes, 2005Co-Authors: Karsten Neumann, Steffen Maak, Peter Fritzsche, Rolf GattermannAbstract:Ten polymorphic microsatellites were developed for the golden hamster (Mesocricetus auratus), a widely used model organism in biological and medical researches. All loci were used to analyse the microsatellite variability in wild golden hamsters from Syria and in a sample of domestic animals comprising different strains. Average mean expected heterozygosity (HE) and mean allele number (A) of domestic hamsters measured 0.279 ± 0.058 and 2.6 ± 0.306, respectively, compared to 0.809 ± 0.019 and 8.3 ± 1.075 found for wild hamsters. Cross-species application in other Mesocricetus species proved conservation of most loci throughout the genus.
-
Notes on the current distribution and the ecology of wild golden hamsters ( Mesocricetus auratus )
Journal of Zoology, 2001Co-Authors: Rolf Gattermann, Karsten Neumann, Peter Fritzsche, I. Al-hussein, A. Kayser, M. Abiad, R. YaktiAbstract:Two expeditions were carried out during September 1997 and March 1999 to confirm the current existence of Mesocricetus auratus in northern Syria. Six females and seven males were caught at different sites near Aleppo. One female was pregnant and gave birth to six pups. Altogether, 30 burrows were mapped and the structures of 23 golden hamster burrows investigated. None of the inhabited burrows contained more than one adult. Burrow depths ranged from 36 to 106 cm (mean 65 cm). Their structure was simple, consisting of a single vertical entrance (gravity pipe) that proceeded to a nesting chamber and at least one additional food chamber. The mean length of the entire gallery system measured 200 cm and could extend up to 900 cm. Most burrows were found on agricultural fields preferentially on leguminous cultures. The distribution of golden hamsters is discussed in association with historical data, soil types, geography, climate and human activities. All 19 golden hamsters were transferred to Germany and, together with three wild individuals supplied by the University of Aleppo, form a new breeding stock.
-
activity rhythms of wild and laboratory golden hamsters Mesocricetus auratus under entrained and free running conditions
Chronobiology International, 2001Co-Authors: D Weinert, Peter Fritzsche, Rolf GattermannAbstract:The golden hamster (Mesocricetus auratus) is one of the most frequently used laboratory animals, particularly in chronobiological studies. One reason is its very robust and predictable rhythms, although the question arises whether this is an inbreeding effect or rather is typical for the species. We compared the daily (circadian) activity rhythms of wild and laboratory golden hamsters. The laboratory hamsters were derived from our own outbred stock (Zoh:GOHA). The wild hamsters included animals captured in Syria and their descendants (F1). Experiments were performed under entrained (light: dark [LD] 14h:10h) and under free-running (constant darkness, DD) conditions. Locomotor activity was recorded using passive infrared detectors. Under entrained conditions, the animals had access to a running wheel for a certain time to induce additional activity. After 3 weeks in constant darkness, a light pulse (15 min, 100 lux) was applied at circadian time 14 (CT14). Both laboratory and wild hamsters showed well-pron...
Robert E. Johnston - One of the best experts on this subject based on the ideXlab platform.
-
cross species discrimination of individual odors by hamsters muridae Mesocricetus auratus phodopus campbelli
Ethology, 2010Co-Authors: Robert E. Johnston, Tara A RobinsonAbstract:Golden hamsters, Mesocricetus auratus, and Djungarian hamsters, Phodopus campbelli, Muridae, were tested for the ability to discriminate between individual odors from both their own species and the other species. Hamsters were tested using an habituation technique, in which differences in time spent investigating familiar and novel scents indicate discrimination of individual differences. Both species showed similar patterns of results when tested with flank gland scents from golden hamsters and ventral gland scents from Djungarian hamsters: The duration of investigation of samples from the same individual scent donor declined over trials, indicating recognition of this scent, but then increased when a scent from a novel individual was presented, indicating discrimination of individual differences. Thus, the capacity and tendency to respond differentially to signals from different individuals is not confined to a single species, suggesting the lack of species-specificity in the signals and perceptual mechanisms involved in individual recognition by scent. This capacity may be common in mammals, and if so suggests the possibility for considerable knowledge of heterospecific individuals.
-
How golden hamsters (Mesocricetus auratus) discriminate top from bottom flank scents in over-marks.
Journal of Comparative Psychology, 2001Co-Authors: Adam B. Cohen, Robert E. Johnston, Anne KwonAbstract:Using a habituation-discrimination paradigm, the authors investigated what cues male golden hamsters (Mesocricetus auratus) use to determine the top and bottom positions in flank gland over-marks. A difference in the ages of 2 hamsters' marks did not, by itself, produce differential memory or evaluation of the 2 scents. A spatial configuration of marks suggestive of an overlap was sufficient for the apparently overlapping scent to be remembered or valued more than the apparently underlying scent. Cues from the overlap of 2 hamsters' marks were also sufficient. These results, consistent with those previously found for responses to hamster vaginal scent over-marks, suggest that hamsters use similar cues to analyze scent over-marks that are different in chemical composition and in social functions.
-
The role of the hippocampal system in social odor discrimination and scent-marking in female golden hamsters (Mesocricetus auratus).
Behavioral Neuroscience, 2000Co-Authors: Aras Petrulis, Marlene Peng, Robert E. JohnstonAbstract:Female golden hamsters (Mesocricetus auratus) received aspiration lesions of the parahippocampal region (PARA) or electrolytic lesions of the fimbria-fornix (FNX) and were tested for their (a) discrimination between odors of individual males in a habituation-discrimination task, (b) preference for male over female odors, and (c) scent-marking in response to conspecific odors. Both lesion groups habituated to repeated presentations of a male's odor. However, only FNX females discriminated between scents of individual males, whereas PARA females did not. Neither lesion eliminated female preferences for male odors. Females with FNX lesions showed decreased levels of scent marking, but those with PARA lesions had more subtle deficits. Thus, the PARA, but not the subcortical connections of the hippocampus, is critical for discrimination of the odors of individuals.
-
Scent counter-marks: specialized mechanisms of perception and response to individual odors in golden hamsters (Mesocricetus auratus).
Journal of Comparative Psychology, 1995Co-Authors: Robin M. Wilcox, Robert E. JohnstonAbstract:Scent counter-marking is a wide-spread phenomenon among mammals that is not well understood. Using a habituation paradigm, it was found that male golden hamsters (Mesocricetus auratus) exposed to partially overlapping scents of 2 females behaved on test trials as if they remembered the top scent but not the bottom scent. If the 2 females' scents did not overlap during exposure trials, males remembered both of them. Thus, if 2 individual scents partially overlap, hamsters (a) perceive which of the 2 scents was deposited most recently and (b) either remember the top scent and forget the bottom scent or attach greater significance to the top scent. These results indicate the existence of specialized perceptual and cognitive or motivational mechanisms that are used for interpretation and response to complex arrays of social odors.
-
Memory for individual scent in hamsters (Mesocricetus auratus) as assessed by habituation methods.
Journal of Comparative Psychology, 1993Co-Authors: Robert E. JohnstonAbstract:The memory of hamsters (Mesocricetus auratus) for the flank scent of other male hamsters was investigated in a series of habituation experiments. In 2 types of habituation tasks (Experiments 1 and 2), male hamsters habituated to the flank scent of 1 male and then increased their level of investigation to that of a novel male; similar results were obtained when the intervals between trials ranged from 1 s to 2 days. When the test trial was 10 or 21 days after habituation (Experiment 3), males discriminated between familiar and novel flank scents at 10 days but not at 21 days. The results demonstrate recognition of familiar and unfamiliar individual odors and excellent memory for these differences. Habituation techniques yield extremely robust results and may be useful for investigations of other aspects of individual signatures.
B. Fried - One of the best experts on this subject based on the ideXlab platform.
-
The effect of dexamethasone on the course ofEchinostoma caproni andE. trivolvis infections in the golden hamster (Mesocricetus auratus)
Parasitology Research, 1995Co-Authors: R. P. Mcmaster, J. E. Huffman, B. FriedAbstract:Golden hamsters ( Mesocricetus auratus ) were given intramuscular injections of dexamethasone and infected with Echinostoma caproni or E. trivolvis . All animals were necropsied on day 14 postinfection. Dexamethasone treatment at high doses resulted in increased parasite recovery. Decreased total white blood cell counts and decreased relative splenic weights were observed in corticosteroid-treated hamsters. Dexamethasone-treated animals also demonstrated significantly lower mean parasite dry weights for E. caproni . Specific serum IgG against the parasites was not detected in corticosteroid-treated hamsters on day 14 postinfection.
Michael G. Katze - One of the best experts on this subject based on the ideXlab platform.
-
Sequencing, Annotation and Analysis of the Syrian Hamster (Mesocricetus auratus) Transcriptome
2016Co-Authors: Nicolas Tchitchek, David Safronetz, Angela L. Rasmussen, Craig Martens, Kimmo Virtaneva, Stephen F. Porcella, Heinz Feldmann, Hideki Ebihara, Michael G. KatzeAbstract:Background: The Syrian hamster (golden hamster, Mesocricetus auratus) is gaining importance as a new experimental animal model for multiple pathogens, including emerging zoonotic diseases such as Ebola. Nevertheless there are currently no publicly available transcriptome reference sequences or genome for this species. Results: A cDNA library derived from mRNA and snRNA isolated and pooled from the brains, lungs, spleens, kidneys, livers, and hearts of three adult female Syrian hamsters was sequenced. Sequence reads were assembled into 62,482 contigs and 111,796 reads remained unassembled (singletons). This combined contig/singleton dataset, designated as the Syrian hamster transcriptome, represents a total of 60,117,204 nucleotides. Our Mesocricetus auratus Syrian hamster transcriptome mapped to 11,648 mouse transcripts representing 9,562 distinct genes, and mapped to a similar number of transcripts and genes in the rat. We identified 214 quasi-complete transcripts based on mouse annotations. Canonical pathways involved in a broad spectrum of fundamental biological processes were significantly represented in the library. The Syrian hamster transcriptome was aligned to the current release of the Chinese hamster ovary (CHO) cell transcriptome and genome to improve the genomic annotation of this species. Finally, our Syrian hamster transcriptome was aligned against 14 other rodents, primate and laurasiatheria species to gain insights about the genetic relatedness and placement of this species
-
Sequencing, annotation and analysis of the Syrian hamster (Mesocricetus auratus) transcriptome.
PLOS ONE, 2014Co-Authors: Nicolas Tchitchek, David Safronetz, Angela L. Rasmussen, Craig Martens, Kimmo Virtaneva, Stephen F. Porcella, Heinz Feldmann, Hideki Ebihara, Michael G. KatzeAbstract:Background The Syrian hamster (golden hamster, Mesocricetus auratus) is gaining importance as a new experimental animal model for multiple pathogens, including emerging zoonotic diseases such as Ebola. Nevertheless there are currently no publicly available transcriptome reference sequences or genome for this species. Results A cDNA library derived from mRNA and snRNA isolated and pooled from the brains, lungs, spleens, kidneys, livers, and hearts of three adult female Syrian hamsters was sequenced. Sequence reads were assembled into 62,482 contigs and 111,796 reads remained unassembled (singletons). This combined contig/singleton dataset, designated as the Syrian hamster transcriptome, represents a total of 60,117,204 nucleotides. Our Mesocricetus auratus Syrian hamster transcriptome mapped to 11,648 mouse transcripts representing 9,562 distinct genes, and mapped to a similar number of transcripts and genes in the rat. We identified 214 quasi-complete transcripts based on mouse annotations. Canonical pathways involved in a broad spectrum of fundamental biological processes were significantly represented in the library. The Syrian hamster transcriptome was aligned to the current release of the Chinese hamster ovary (CHO) cell transcriptome and genome to improve the genomic annotation of this species. Finally, our Syrian hamster transcriptome was aligned against 14 other rodents, primate and laurasiatheria species to gain insights about the genetic relatedness and placement of this species. Conclusions This Syrian hamster transcriptome dataset significantly improves our knowledge of the Syrian hamster's transcriptome, especially towards its future use in infectious disease research. Moreover, this library is an important resource for the wider scientific community to help improve genome annotation of the Syrian hamster and other closely related species. Furthermore, these data provide the basis for development of expression microarrays that can be used in functional genomics studies.
R. P. Mcmaster - One of the best experts on this subject based on the ideXlab platform.
-
The effect of dexamethasone on the course ofEchinostoma caproni andE. trivolvis infections in the golden hamster (Mesocricetus auratus)
Parasitology Research, 1995Co-Authors: R. P. Mcmaster, J. E. Huffman, B. FriedAbstract:Golden hamsters ( Mesocricetus auratus ) were given intramuscular injections of dexamethasone and infected with Echinostoma caproni or E. trivolvis . All animals were necropsied on day 14 postinfection. Dexamethasone treatment at high doses resulted in increased parasite recovery. Decreased total white blood cell counts and decreased relative splenic weights were observed in corticosteroid-treated hamsters. Dexamethasone-treated animals also demonstrated significantly lower mean parasite dry weights for E. caproni . Specific serum IgG against the parasites was not detected in corticosteroid-treated hamsters on day 14 postinfection.
-
The effect of dexamethasone on the course of Echinostoma caproni and E. trivolvis infections in the golden hamster (Mesocricetus auratus).
Parasitology Research, 1995Co-Authors: R. P. Mcmaster, Jane E Huffman, Bernard FriedAbstract:Golden hamsters (Mesocricetus auratus) were given intramuscular injections of dexamethasone and infected withEchinostoma caproni orE. trivolvis. All animals were necropsied on day 14 postinfection. Dexamethasone treatment at high doses resulted in increased parasite recovery. Decreased total white blood cell counts and decreased relative splenic weights were observed in corticosteroid-treated hamsters. Dexamethasone-treated animals also demonstrated significantly lower mean parasite dry weights forE. caproni. Specific serum IgG against the parasites was not detected in corticosteroid-treated hamsters on day 14 postinfection.