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At least 19 recordsLinked to original sources
PubMed1984

[Spontaneous and experimental infection of alpine marmots (Marmota marmota) by the North American woodchuck hepatitis virus (Marmota monax). Initial results].

Summer's discovery in 1978 of a DNA virus, very close to human Hepatitis B virus in a woodchuck population in the U.S.A. (Pennsylvania) was a confirmation of the first description made by Snyder at Penrose Research Laboratory (Philadelphia). It was the first animal model of human B hepatitis infection. The comparative study of morphological, ecological and ethological characteristics of the marmot (Marmota marmota) and the woodchuck (Marmota monax) enables an easy distinction between these two species. The natural infection of M. monax by the WHV shows that the woodchuck is a good model for human B hepatitis and should be extended to M. marmota. A sample of 24 marmots caught in the Alpes of Haute-Provence has not revealed any spontaneous infection in these animals by the woodchuck virus. The failure of experimental inoculation of the marmot (24 animals) with the WHV confirms the refractory status of this species (no viremia and very low and short serological response with or without an immunosuppressive treatment). These preliminary results require a confirmation in other animals of different age and geographical region and also by using more specific tests such as molecular hybridization, research on DNA polymerase and direct transfection trials.

Age Factors↗
PubMed1986

The primary structure of the hemoglobin of the European marmot (Marmota marmota marmota, Rodentia).

The hemoglobin of the European marmot Marmota marmota marmota has been found to consist of only one component. In this work, we are presenting its primary structure. The globin chains have been separated by high performance liquid chromatography and the sequences have been determined by automated Edman degradation of the chains and their tryptic peptides, as well as of the peptide obtained by acid hydrolysis of the Asp-Pro bond in the beta-chains. In the alpha-chains we have found 13 and in the beta-chains 34 exchanges compared with the human alpha- and beta-chains, respectively. The amino acids which are substituted in the alpha-chains are not involved in any contacts, whereas in the beta-chains, one exchange involves a heme contact, two alpha 1/beta 1- and one alpha 1/beta 2-contacts. The functional and evolutionary aspects of these findings are discussed.

Amino Acid Sequence↗
PubMed2002

Seasonal changes in morphology and function of the gastrointestinal tract of free-living alpine marmots ( Marmota marmota).

The gastrointestinal tracts of 76 free-living alpine marmots ( Marmota marmota) shot during a population control program in Switzerland were collected and analysed for patterns of change in morphology and function over the period from emergence from hibernation in April to just before re-entry into hibernation in September. Between first emergence and mid-summer (July) the fresh tissue mass of the stomach increased by 105%, the small intestine by 259% (among the largest recorded for a mammal), caecum by 185%, proximal colon by 138%, and distal colon by 144%. Mitotic activity was greatest in the small intestine; the mitotic index was high (40%) compared with indexes in the stomach and hindgut (approximately 4%) even at emergence, and increased to approximately 60% by mid-summer. Microbial activity in the caecum was also significant at emergence. The stomach (length) and caecum (length and fresh mass) increased in response to ingested food earlier than did the small intestine. Between mid-summer and September there were decreases in small intestinal tissue mass and mitotic activity. It is concluded that the gastrointestinal tract of alpine marmots probably continues to function throughout hibernation at a low level, with a mid-winter trough as part of an endogenous circannual rhythm. However, after emergence in spring, increases in size and activity of the tract appear to be a response to ingested food rather than to an endogenous signal. The early signs of down-regulation of the small intestine before re-entry into hibernation, together with its delayed up-regulation in response to food in spring, are consistent with the high costs of maintaining this section of the digestive system.

Animals↗
PubMed1978

Survey of keratinophilic fungi in Alpine marmot (Marmota marmota) burrow soil and in adjoining soils.

Soil samples from 127 marmot (Marmota marmota) burrows were examined for keratinophilic fungi along with 48 soil samples from adjoining areas. The occurrence of keratinophilic fungi (especially Microsporum gypseum) was significantly higher in burrow soil. A review of the literature and our results support the hypothesis that the "animalization" (i.e. the enrichment of soil with hairs, crusts and other organic matters) of the environment may create conditions suitable for the growth of keratinophilic fungi. The presence of keratinophilic fungi in alpine mountain soil was noted for the first time.

Animals↗
PubMed1994

Low genetic variability in a natural alpine marmot population (Marmota marmota, Sciuridae) revealed by DNA fingerprinting.

Genetic heterogeneity is usually considered an important factor for the viability of a population, yet there are cases in which populations sustain themselves despite virtual homozygosity. A prior step to studying the effects of such low levels of genetic variability can be the analysis of its causes. We analysed a population of the highly social alpine marmot (Marmota marmota, Sciuridae) by multilocus DNA fingerprinting. The fingerprint patterns revealed a very low degree of polymorphism in our main study population. We show that this lack of hypervariability is caused by a low effective population size, rather than by an unusual low mutation rate of the fingerprint loci studied. However, the current number of breeding pairs was found to be about an order of magnitude larger than the one that would be expected to lead to such a low degree of heterozygosity. We conclude that there must have been bottlenecks in the history of the Berchtesgaden marmot population that have severely affected its genetic heterozygosity.

Animals↗
PubMed2000

Identification of odorant receptors from the Alpine marmot (Marmota marmota).

Alpine Marmots (Marmota marmota) are a good model to study intraspecific chemical communication among mammals. This species has been subjected to several behavioural and biochemical studies regarding both their scent-marking behaviour by cheek-rubbing, and the chemical composition of their glandular secretions. However, no molecular study has been undertaken until today on proteins from the olfactory epithelium possibly implicated in chemical perception. In this study, we identified, to our knowledge for the first time, some olfatory receptors from this wild rodent. Starting with olfactory epithelium of an Alpine Marmot, and by mean of reverse transcriptase polymerase chain reaction technique (RT-PCR), we isolated fourteen partial sequences that exhibited a high degree of homology (45-92%) with olfactory receptors from other vertebrates. Conserved identities and structural features clearly defined these Alpine Marmot sequences as members of the seven transmembrane domain olfactory receptors. All sequences were observed as belonging to known olfactory receptor families and were classified into ten subfamilies of the tetrapods OR class. Finally, Northern blot analysis revealed specific expression of these sequences in the Alpine Marmot olfactory epithelium tissue.

Amino Acid Sequence↗
PubMed1988

The ultrastructure of the thyroid parafollicular cells of the marmot (Marmota marmota). Immunocytochemical localization of calcitonin and somatostatin.

We studied the topographical and ultrastructural characteristics of the parafollicular cells in the Marmota marmota and their seasonal changes. The parafollicular cells, together with the follicular cells, form the follicular epithelium occupying a peculiar basal position. Furthermore these cells are characterized by a clear cytoplasmic matrix and well developed cytoplasmic organelles. The latter synthesize and condense the secretory product which ultrastructurally is organized in secretory granule-vesicles with a scarcely electron-dense cottony content. Histochemically the secretion consists in a proteic complex (rich in alpha-amino acids and sulphonate proteins) with a minor glucidic component. The above metabolic activity closely relates with the seasonal metabolic changes and namely with calcium metabolism. The immunocytochemical reactions revealed the presence of calcitonin and, to a lesser extent, somatostatin. The morphological findings were compared with those observed in other hibernating mammalians and related to the calcium homeostasis.

Animals↗
PubMed1988

Social thermoregulation during hibernation in alpine marmots (Marmota marmota).

Body temperature (Tb) of socially hibernating alpine marmots, a pair and two family groups, was monitored continuously from October to March with implanted temperature-sensitive radiotransmitters. At the same time, the animals' behaviour was observed. The recurrent entrances into and arousals from hibernation were highly synchronised within groups. Group members always lay huddled together when euthermic and also when torpid with a few exceptions at higher ambient temperatures (Ta). Body contact with euthermic nestmates warmed torpid marmots passively. The Tb of animals reentering hibernation did not fall to values close to Ta as long as euthermic group members were present. Although animals presumably save energy through social thermoregulation, especially when euthermic, these benefits are not necessarily mutual among group members. Differences in thermoregulatory behaviour of individuals described in this study could be responsible for differential weight losses during winter as found in the natural habitat (Arnold 1986).

Animals↗
PubMed2000

Regulation of body temperature and energy requirements of hibernating alpine marmots (Marmota marmota).

Body temperature and metabolic rate were recorded continuously in two groups of marmots either exposed to seasonally decreasing ambient temperature (15 to 0 degrees C) over the entire hibernation season or to short-duration temperature changes during midwinter. Hibernation bouts were characterized by an initial 95% reduction of metabolic rate facilitating the drop in body temperature and by rhythmic fluctuations during continued hibernation. During midwinter, we observed a constant minimal metabolic rate of 13.6 ml O(2) x kg(-1) x h(-1) between 5 and 15 degrees C ambient temperature, although body temperature increased from 7.8 to 17.6 degrees C, and a proportional increase of metabolic rate below 5 degrees C ambient temperature. This apparent lack of a Q(10) effect shows that energy expenditure is actively downregulated and controlled at a minimum level despite changes in body temperature. However, thermal conductance stayed minimal (7.65 +/- 1.95 ml O(2) x kg(-1) x h(-1) x degrees C(-1)) at all temperatures, thus slowing down cooling velocity when entering hibernation. Basal metabolic rate of summer-active marmots was double that of winter-fasting marmots (370 vs. 190 ml O(2) x kg(-1) x h(-1)). In summary, we provide strong evidence that hibernation is not only a voluntary but a well-regulated strategy to counter food shortage and increased energy demands during winter.

Animals↗
PubMed1976

[Oribatids (Oribatei, Acari) as intermediate hosts of Ctenotaenia marmotae (Frölich, 1802), a tapeworm parasitic in marmots (author's transl)].

Out of 30 species of Oribatids (from 23 genera), which were provided with eggs of Ctenotaenia marmotae in the laboratory, 24 proved to be potential intermediate hosts. The course of development of the parasite in the intermediate host could be followed up as far as to the cysticercoid (Figs. 2-8). It largely corresponds to the development of other Anoplocephalidae. After 113 days p.i. (test temperature 18-20 degrees C) the cysticercoid stage was reached. In the Pölla valley (Carinthia), at sea level of 2,200 m, the droppings of marmots scattered on the grass andmingled with proglottids of C. marmotae were marked. 9 months later 24 grass samples were taken and examined as to infected Oribatids. Out of a total of 12,100 specimens 49 turned out to be infected with cysticercoids; these specimens, however, belong to the species of Trichoribates incisellus (Kramer) and Trichoribates trimaculatus (C.L. Koch). They were taken from 16 samples with a total of 8,400 Oribatids. This is the first evidence under natural conditions of Oribatids acting as intermediate hosts to C. marmotae. It is presumed that 2 seasonal invasion peaks occur in the final host Marmota marmota (L.).

Animals↗
PubMed2026

Complete genome sequence of an antibiotic-resistant and virulent Escherichia marmotae isolate recovered from a urinary tract infection.

OBJECTIVES: We aimed at analyzing the whole genome of the antibiotic-resistant Escherichia marmotae isolate 23-MO01035-0, which was obtained from a urinary tract infection of a male patient in Germany. The study focused on the characterization of mobile genetic elements and genetic factors that contribute to antibiotic resistance and pathogenicity. METHODS: Phenotypic antimicrobial susceptibility testing was performed and genomic DNA was sequenced using Illumina NextSeq (2 × 151 bp) and a MinION Mk1C device followed by de novo hybrid assembly using Unicycler v0.4.8. Resistance genes, virulence factors, plasmids, and mobile elements were identified with the bakcharak pipeline and PathogenFinder. RESULTS: The isolate belonged to sequence type ST133 and the 5,041,084 bp whole genome, consisting of one chromosome and five plasmids with an average GC content of 50.4%, revealed resistance genes for various antibiotic classes on an IncFII plasmid that had not yet been described. The isolate was predicted to be a potential human pathogen due to the presence of multiple virulence genes. CONCLUSION: Here, we report one of the first detailed genomic characterization of an antibiotic-resistant and virulent E. marmotae isolate from Germany. Considering that this bacterium was isolated from the urinary tract and possibly belonged to the faecal microbiota of the patient at that time, E. marmotae might contribute to the spread of antibiotic resistance in humans. This underscores the importance of genomic surveillance of E. marmotae, which causes human infections, but may be misidentified as E. coli.

Escherichia marmotae↗