A non-LTR retroelement extinction in Spermophilus tridecemlineatus

Gene ◽  
2012 ◽  
Vol 500 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Roy N. Platt II ◽  
David A. Ray
Keyword(s):  
Spermophilus Tridecemlineatus

Differential expression of mitochondria-encoded genes in a hibernating mammal

2002 ◽  
Vol 205 (11) ◽  
pp. 1625-1631 ◽  
Author(s):  
Dustin S. Hittel ◽  
Kenneth B. Storey
Keyword(s):  
Differential Expression ◽  
Atp Synthase ◽  
Fold Increase ◽  
Immunoblot Analysis ◽  
Northern Blotting ◽  
Spermophilus Tridecemlineatus ◽  
Transcript Levels ◽  
Multiple Organs ◽  
Transport Chain ◽  
Brown Adipose

SUMMARYA cDNA library constructed from kidney of the thirteen-lined squirrel, Spermophilus tridecemlineatus, was differentially screened for genes that were upregulated during hibernation. A clone encoding cytochrome c oxidase subunit 1 was found and confirmed to have been upregulated by northern blotting. Differential expression of Cox1 mRNA occurred in multiple organs during hibernation; in hibernating animals transcript levels were twofold higher in kidney and fourfold higher in heart and brown adipose tissue than in euthermic animals, but were unchanged in skeletal muscle. Transcript levels of mitochondrial-encoded ATP synthase 6/8 were similarly upregulated in these tissues whereas transcript levels of the nuclear encoded subunits Cox4 and ATP synthase α did not change during hibernation. Immunoblot analysis revealed a 2.4-fold increase in Cox 1 protein and a slight decrease in Cox 4 protein in kidney of hibernating squirrels, compared with euthermic controls. Hibernating mammals may increase the expression of the mitochondrial genome in general, and Cox1specifically, to prevent or minimize the damage to the electron transport chain caused by the cold and ischemia experienced during a hibernation bout.

scholarly journals Circulation and metabolic rates in a natural hibernator: an integrative physiological model

2010 ◽  
Vol 299 (6) ◽  
pp. R1478-R1488 ◽  
Author(s):  
Marshall Hampton ◽  
Bethany T. Nelson ◽  
Matthew T. Andrews
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Core Body Temperature ◽  
Circulatory System ◽  
Physiological Model ◽  
Ground Squirrels ◽  
Metabolic Rates ◽  
Spermophilus Tridecemlineatus ◽  
Brown Adipose ◽  
Core Body

Small hibernating mammals show regular oscillations in their heart rate and body temperature throughout the winter. Long periods of torpor are abruptly interrupted by arousals with heart rates that rapidly increase from 5 beats/min to over 400 beats/min and body temperatures that increase by ∼30°C only to drop back into the hypothermic torpid state within hours. Surgically implanted transmitters were used to obtain high-resolution electrocardiogram and body temperature data from hibernating thirteen-lined ground squirrels ( Spermophilus tridecemlineatus ). These data were used to construct a model of the circulatory system to gain greater understanding of these rapid and extreme changes in physiology. Our model provides estimates of metabolic rates during the torpor-arousal cycles in different model compartments that would be difficult to measure directly. In the compartment that models the more metabolically active tissues and organs (heart, brain, liver, and brown adipose tissue) the peak metabolic rate occurs at a core body temperature of 19°C approximately midway through an arousal. The peak metabolic rate of the active tissues is nine times the normothermic rate after the arousal is complete. For the overall metabolic rate in all tissues, the peak-to-resting ratio is five. This value is high for a rodent, which provides evidence for the hypothesis that the arousal from torpor is limited by the capabilities of the cardiovascular system.

Seasonal dynamics and distribution of American dog tick, Dermacentor variabilis (Say), larvae and nymphs at Birds Hill Park, Manitoba

1985 ◽  
Vol 63 (12) ◽  
pp. 2748-2755 ◽  
Author(s):  
V. I. Burachynsky ◽  
T. D. Galloway
Keyword(s):  
Dermacentor Variabilis ◽  
Microtus Pennsylvanicus ◽  
Tamiasciurus Hudsonicus ◽  
Clethrionomys Gapperi ◽  
Spermophilus Tridecemlineatus ◽  
Mammal Species ◽  
Tamias Striatus ◽  
Sorex Cinereus ◽  
Spermophilus Franklinii ◽  
Dog Tick

During a 2-year study on the relationships between immature Dermacentor variabilis and their small-mammal hosts near Birds Hill, Manitoba, 739 captures of 427 mammals were examined for ticks. Captures represented 11 mammal species: Clethrionomys gapperi, Lepus americanus, Microtus pennsylvanicus, Mus musculus, Peromyscus maniculatus, Sorex cinereus, Spermophilus franklinii, Spermophilus tridecemlineatus, Tamias striatus, Tamiasciurus hudsonicus, and Zapus hudsonius. Clethrionomys gapperi, M. pennsylvanicus, P. maniculatus, S. franklinii, and Z. hudsonius were most frequently encountered and, with the exception of S. franklinii, infested with larvae and nymphs. Clethrionomys gapperi were most frequently infested by D. variabilis and produced 42.6% and 60.5% of larvae collected in 1979 and 1980, respectively, and over 85% of all nymphs. Peak larval infestation occurred between the last week of May and the middle of June; that for nymphs occurred in July in both 1979 and 1980. Dermacentor variabilis appeared to have a 2-year life cycle in Manitoba. Larvae were spatially aggregated during both years and aggregates were located in different areas of the plots each year. Nymphs were less aggregated than larvae. The distribution of nymphs overlapped that of larvae each year and occupied a greater area on the plots.

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