Detection and characterization of a novel hepacivirus in long-tailed ground squirrels (Spermophilus undulatus) in China

2019 ◽  
Vol 164 (9) ◽  
pp. 2401-2410 ◽  
Author(s):  
Li-li Li ◽  
Meng-meng Liu ◽  
Shu Shen ◽  
Yu-jiang Zhang ◽  
Ya-long Xu ◽  
...  
Keyword(s):  
Ground Squirrels ◽  
Spermophilus Undulatus

Characterization of midbrain component of the trigger for arousal from hibernation

1976 ◽  
Vol 230 (2) ◽  
pp. 368-375 ◽  
Author(s):  
AL Beckman ◽  
E Satinoff ◽  
TL Stanton
Keyword(s):  
Body Temperature ◽  
Ambient Temperature ◽  
Reticular Formation ◽  
Functional Organization ◽  
Ground Squirrels ◽  
Anterior Hypothalamus ◽  
Midbrain Reticular Formation ◽  
Citellus Lateralis ◽  
Arousal Mechanism

The ability of the midbrain reticular formation (MRF) to trigger arousal from hibernation and to change body temperature (Tb) during euthermia was tested in golden-mantled ground squirrels (Citellus lateralis). During hibernation (ambient temperature 5-6 degrees C) microinjections of cholinomimetic compounds (acetylcholine and carbachol) triggered full arousal or produced transient increases in Tb in 15 out of 19 tests; MRF microinjections of norepinephrine (NE) and 5-hydroxytryptamine (5-HT), at the same concentrations that produced full arousal when microinjected into the preoptic/anterior hypothalamus (PO/AH) area in previous experiments, has no effect on Tb in 13 out of 16 tests. In experiments on euthermic ground squirrels tested at an ambient temperature of 25 degrees C, MRF microinjections of acetylcholine raised Tb, whereas the monoamines had no significant effects. These results show that cholinoceptive neurons in the MRF can trigger arousal from hibernation and increase Tb during euthermia. The failure of NE and 5-HT to produce any significant effects at the same doses that were reported to be effective in the PO/AH indicates that the functional organization of the MRF portion of the arousal mechanism is different from that reported for the PO/AH.

scholarly journals Ca-ATPase Activity and Protein Composition of Sarcoplasmic Reticulum Membranes Isolated from Skeletal Muscles of Typical Hibernator, the Ground Squirrel Spermophilus undulatus

2001 ◽  
Vol 21 (6) ◽  
pp. 831-838 ◽  
Author(s):  
Anna N. Malysheva ◽  
Kenneth B. Storey ◽  
Olga D. Lopina ◽  
Alexander M. Rubstov
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Atpase Activity ◽  
Electrophoretic Mobility ◽  
Ground Squirrel ◽  
Skeletal Muscles ◽  
Binding Proteins ◽  
Protein Composition ◽  
Ground Squirrels ◽  
Ground Squirrel Spermophilus Undulatus ◽  
Spermophilus Undulatus

Ca-ATPase activity in sarcoplasmic reticulum (SR) membranes isolated from skeletal muscles of the typical hibernator, the ground squirrel Spermophilus undulatus, is about 2-fold lower than that in SR membranes of rats and rabbits and is further decreased 2-fold during hibernation. The use of carbocyanine anionic dye Stains-All has revealed that Ca-binding proteins of SR membranes, histidine-rich Ca-binding protein and sarcalumenin, in ground squirrel, rat, and rabbit SR have different electrophoretic mobility corresponding to apparent molecular masses 165, 155, and 170 kDa and 130, 145, and 160 kDa, respectively; the electrophoretic mobility of calsequestrin (63 kDa) is the same in all preparations. The content of these Ca-binding proteins in SR membranes of the ground squirrels is decreased 3–4 fold and the content of 55, 30, and 22 kDa proteins is significantly increased during hibernation.

scholarly journals Characterization of captive and wild 13-lined ground squirrel cecal microbiotas using Illumina-based sequencing

2022 ◽  
Vol 4 (1) ◽  
Author(s):  
Edna Chiang ◽  
Courtney L. Deblois ◽  
Hannah V. Carey ◽  
Garret Suen
Keyword(s):  
16S Rrna ◽  
Beta Diversity ◽  
Current Knowledge ◽  
Winter Season ◽  
Ground Squirrels ◽  
Rrna Gene ◽  
Active Season ◽  
Operational Taxonomic Units ◽  
The 16S Rrna Gene

Abstract Background Hibernating animals experience extreme changes in diet that make them useful systems for understanding host-microbial symbioses. However, most of our current knowledge about the hibernator gut microbiota is derived from studies using captive animals. Given that there are substantial differences between captive and wild environments, conclusions drawn from studies with captive hibernators may not reflect the gut microbiota’s role in the physiology of wild animals. To address this, we used Illumina-based sequencing of the 16S rRNA gene to compare the bacterial cecal microbiotas of captive and wild 13-lined ground squirrels (TLGS) in the summer. As the first study to use Illumina-based technology to compare the microbiotas of an obligate rodent hibernator across the year, we also reported changes in captive TLGS microbiotas in summer, winter, and spring. Results Wild TLGS microbiotas had greater richness and phylogenetic diversity with less variation in beta diversity when compared to captive microbiotas. Taxa identified as core operational taxonomic units (OTUs) and found to significantly contribute to differences in beta diversity were primarily in the families Lachnospiraceae and Ruminococcaceae. Captive TLGS microbiotas shared phyla and core OTUs across the year, but active season (summer and spring) microbiotas had different alpha and beta diversities than winter season microbiotas. Conclusions This is the first study to compare the microbiotas of captive and wild rodent hibernators. Our findings suggest that data from captive and wild ground squirrels should be interpreted separately due to their distinct microbiotas. Additionally, as the first study to compare seasonal microbiotas of obligate rodent hibernators using Illumina-based 16S rRNA sequencing, we reported changes in captive TLGS microbiotas that are consistent with previous work. Taken together, this study provides foundational information for improving the reproducibility and experimental design of future hibernation microbiota studies.

Hypothermia-induced spatially discordant action potential duration alternans and arrhythmogenesis in nonhibernating versus hibernating mammals

2012 ◽  
Vol 303 (8) ◽  
pp. H1035-H1046 ◽  
Author(s):  
Yuriy V. Egorov ◽  
Alexey V. Glukhov ◽  
Igor R. Efimov ◽  
Leonid V. Rosenshtraukh
Keyword(s):  
Action Potential ◽  
Action Potential Duration ◽  
Conduction Block ◽  
Ground Squirrels ◽  
Dispersion Of Repolarization ◽  
Epicardial Surface ◽  
Cardiac Alternans ◽  
Spermophilus Undulatus ◽  
Perfused Hearts ◽  
Low Dispersion

The heart of hibernating species is resistant to lethal ventricular fibrillation (VF) induced by hypothermia. Spatially discordant (SDA) cardiac alternans is a promising predictor of VF, yet its role in the mechanism of hypothermic arrhythmogenesis in both nonhibernating and hibernating mammals remains unclear. We optically mapped the posterior epicardial surface of Langendorff-perfused hearts of winter hibernating (WH, n = 13), interbout arousal (IBA; n = 4), and summer active (SA, n = 6) ground squirrels (GSs; Spermophilus undulatus) and rabbits ( n = 10). Action potential duration (APD) and conduction velocity (CV) dynamic restitution and alternans were determined at 37 to 17°C. In all animals, hypothermia induced heterogeneous APD prolongation, enhanced APD dispersion, and slowed CV. In all groups, hypothermia promoted the formation of APD alternans, which was predominantly spatially concordant in GSs and SDA in rabbits (SD of APD dispersion: 4.2 ± 0.4% vs. 2.0 ± 0.3% at 37°C and 7.5 ± 1.1% vs. 3.4 ± 0.5% at 17°C, P < 0.001 for rabbits vs. the WH group, respectively). In rabbits, hypothermia significantly increased the magnitude of SDA, which enhanced the ventricular repolarization gradient, caused conduction delays (CV: 3.2 vs. 8.2 cm/s at 17°C in rabbits vs. the WH group), conduction block, and the onset of VF (0% at 37°C vs. 60% at 17°C, P < 0.01). In contrast, no arrhythmia was observed in GS hearts at any temperature. The amplitude of CV alternans was greater in rabbits (5.2 ± 0.4% versus 4.5 ± 0.3% at 37°C and 35.3 ± 4.2% vs. 14.9 ± 1.5% at 17°C in rabbits vs. the WH group, P < 0.001 at 17°C) and correlated with the amplitude of SDA. In conclusion, the mechanism underlying SDA formation during hypothermia is likely associated with CV alternans conditioned by an enhanced dispersion of repolarization. The factors of hibernating species resistance to SDA and VF seem to be the safe and dynamically stable conduction and the low dispersion of repolarization.

Seasonal changes in the isoform composition of the myosin heavy chains in skeletal muscles of hibernating ground squirrels Spermophilus undulatus

BIOPHYSICS ◽  
2012 ◽  
Vol 57 (6) ◽  
pp. 764-768 ◽  
Author(s):  
M. V. Lazareva ◽  
K. O. Trapeznikova ◽  
I. M. Vikhlyantsev ◽  
A. G. Bobylev ◽  
A. A. Klimov ◽  
...  
Keyword(s):  
Seasonal Changes ◽  
Skeletal Muscles ◽  
Ground Squirrels ◽  
Myosin Heavy Chains ◽  
Heavy Chains ◽  
Spermophilus Undulatus

Ketone bodies: a source of energy during hibernation

1981 ◽  
Vol 59 (5) ◽  
pp. 754-760 ◽  
Author(s):  
Josefine C. Rauch ◽  
Hans W. Behrisch
Keyword(s):  
Ground Squirrel ◽  
Ketone Body ◽  
Ketone Bodies ◽  
Ground Squirrels ◽  
Brown Fat ◽  
Arctic Ground Squirrel ◽  
Tissue Concentrations ◽  
Brown Adipose ◽  
Spermophilus Undulatus ◽  
Arctic Ground Squirrels

Tissue concentrations of acetoacetate and β-hydroxybutyrate (ketone bodies) were determined for the blood, liver, caecum, heart, and axillary brown fat, from nonhibernating and hibernating arctic ground squirrels, Spermophilus undulatus, in late spring and during winter, respectively. AcetylCoA and acetoacetylCoA concentrations were measured in the liver, heart, and brown adipose tissue.Except that the concentration of acetylCoA remained unchanged in the liver, all tissues investigated showed elevated concentrations of acetylCoA, acetoacetylCoA, and ketone bodies during the hibernating state. From the increased concentrations of acetoacetate and β-hydroxybutyrate it was deduced that active ketone body metabolism occurs in the hibernating arctic ground squirrel, and that during hibernation, ketone bodies are probably an important source of energy.

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