| 1. |
|
|
| 2. |
- Ledin, Anna, et al.
(författare)
-
High plasma IgE levels within the Scandinavian wolf population, and its implications for mammalian IgE homeostasis
- 2008
-
Ingår i: Molecular Immunology. - : Elsevier BV. - 0161-5890 .- 1872-9142. ; 45:7, s. 1976-1980
-
Tidskriftsartikel (refereegranskat)abstract
- Immunoglobulin E (IgE) serves as an important link between innate and adaptive immunity through its ability to bind high affinity receptors on mast cells and basophils. Large differences in IgE levels may here affect this important link, and IgE levels in natural non-domestic animal populations may therefore be very informative concerning the levels of IgE that this system have been balanced against during recent mammalian evolution. However, very few such studies have been performed. Here, we present an analysis of total IgE levels in 65 Scandinavian wolves: 57 free living (wild), and 8 wolves in captivity (Zoo). The 57 wild wolves correspond to approximately 30% of the entire wolf population in Sweden and Norway and thus represent a large fraction of the entire population, making this a unique sample from a wild canine population. The median IgE level in these wolves was 67 μg/ml, which is approximately twice the level seen in domestic dogs and more than 100 times the levels in non-atopic humans. The collected information from domestic and wild populations now indicate that the very low IgE levels observed in man and laboratory rodents are most likely an effect of a life in a relatively parasite free environment, and that total IgE levels under maximally stimulatory (normal) conditions may reach 100-200 μg/ml.
|
|
| 3. |
- Axelsson, Erik, et al.
(författare)
-
The genomic signature of dog domestication reveals adaptation to a starch-rich diet
- 2013
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 495:7441, s. 360-364
-
Tidskriftsartikel (refereegranskat)abstract
- The domestication of dogs. was an important episode in the development of human civilization. The precise timing and location of this event is debated(1-5) and little is known about the genetic changes that accompanied the transformation of ancient wolves into domestic dogs. Here we conduct whole-genome resequencimg of dogs and wolves to identify 3.8 million genetic variants used to identify 36 genomic regions that probably represent targets for selection during dog domestication. Nineteen of these regions contain genes important in brain function, eight of which belong to nervous system development pathways and potentially underlie behavioural changes central to dog domestication(6). Ten genes with key roles in starch digestion and fat metabolism also show signals of selection. We identify candidate mutations in key genes and provide functional support for an increased starch digestion in dogs relative to wolves. Our results indicate that novel adaptations allowing the early ancestors of modern dogs to thrive on a diet rich in starch, relative to the carnivorous diet of wolves, constituted a crucial step in the early domestication of dogs.
|
|
| 4. |
- Månsson, Johan, et al.
(författare)
-
Sarcoptic mange in the Scandinavian wolf Canis lupus population
- 2016
-
Ingår i: BMC Veterinary Research. - : Springer Science and Business Media LLC. - 1746-6148. ; 12
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Sarcoptic mange, a parasitic disease caused by the mite Sarcoptes scabiei, is regularly reported on wolves Canis lupus in Scandinavia. We describe the distribution and transmission of this parasite within the small but recovering wolf population by analysing 269 necropsy reports and performing a serological survey on 198 serum samples collected from free-ranging wolves between 1998 and 2013.Results: The serological survey among 145 individual captured Scandinavian wolves (53 recaptures) shows a consistent presence of antibodies against sarcoptic mange. Seropositivity among all captured wolves was 10.1 % (CI. 6.4 %-15.1 %). Sarcoptic mange-related mortality reported at necropsy was 5.6 % and due to secondary causes, predominantly starvation. In the southern range of the population, seroprevalence was higher, consistent with higher red fox densities. Female wolves had a lower probability of being seropositive than males, but for both sexes the probability increased with pack size. Recaptured individuals changing from seropositive to seronegative suggest recovery from sarcoptic mange. The lack of seropositive pups (8-10 months, N = 56) and the occurrence of seropositive and seronegative individuals in the same pack indicates interspecific transmission of S. scabiei into this wolf population.Conclusions: We consider sarcoptic mange to have little effect on the recovery of the Scandinavian wolf population. Heterogenic infection patterns on the pack level in combination with the importance of individual-based factors (sex, pack size) and the north-south gradient for seroprevalence suggests low probability of wolf-to-wolf transmission of S. scabiei in Scandinavia.
|
|
| 5. |
- Singh, Navinder, et al.
(författare)
-
Drivers of hibernation in the brown bear
- 2016
-
Ingår i: Frontiers in Zoology. - : Springer Science and Business Media LLC. - 1742-9994. ; 13
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Hibernation has been a key area of research for several decades, essentially in small mammals in the laboratory, yet we know very little about what triggers or ends it in the wild. Do climatic factors, an internal biological clock, or physiological processes dominate? Using state-of-the-art tracking and monitoring technology on fourteen free-ranging brown bears over three winters, we recorded movement, heart rate (HR), heart rate variability (HRV), body temperature (Tb), physical activity, ambient temperature (TA), and snow depth to identify the drivers of the start and end of hibernation. We used behavioral change point analyses to estimate the start and end of hibernation and convergent cross mapping to identify the causal interactions between the ecological and physiological variables over time.Results: To our knowledge, we have built the first chronology of both ecological and physiological events from before the start to the end of hibernation in the field. Activity, HR, and Tb started to drop slowly several weeks before den entry. Bears entered the den when snow arrived and when ambient temperature reached 0 °C. HRV, taken as a proxy of sympathetic nervous system activity, dropped dramatically once the bear entered the den. This indirectly suggests that denning is tightly coupled to metabolic suppression. During arousal, the unexpected early rise in Tb (two months before den exit) was driven by TA, but was independent of HRV. The difference between Tb and TA decreased gradually suggesting that bears were not thermoconforming. HRV increased only three weeks before exit, indicating that late activation of the sympathetic nervous system likely finalized restoration of euthermic metabolism. Interestingly, it was not until TA reached the presumed lower critical temperature, likely indicating that the bears were seeking thermoneutrality, that they exited the den.Conclusions: We conclude that brown ear hibernation was initiated primarily by environmental cues, but terminated by physiological cues.
|
|
| 6. |
- Arinell, Karin, 1982-, et al.
(författare)
-
Brown Bears (Ursus arctos) Seem Resistant to Atherosclerosis Despite Highly Elevated Plasma Lipids during Hibernation and Active State
- 2012
-
Ingår i: Clinical and Translational Science. - : Wiley-Blackwell. - 1752-8054 .- 1752-8062. ; 5:3, s. 269-272
-
Tidskriftsartikel (refereegranskat)abstract
- Hibernation is an extreme physiological challenge for the brown bear (Ursus arctos) in which metabolism is based mainly on lipids. The study objective was to compare plasma lipids in hibernating and active free-ranging brown bears and relate them to arterial histopathology. Blood was drawn from seven immobilized free-ranging brown bears (three females, 23 years old) during hibernation in February and from the same bears while active in June and analyzed by enzymatic and automated hematology methods within 48 hours of sampling. Left anterior descending coronary arteries and aortic arches from 12 bears (six females, 1.512 years old) killed in hunting were examined by histopathology. Total plasma cholesterol decreased from hibernation to the active period (11.08 +/- 1.04 mmol/L vs. 7.89 +/- 1.96 mmol/L, P= 0.0028) as did triglyceride (3.16 +/- 0.62 mmol/L vs. 1.44 +/- 0.27 mmol/L, P= 0.00012) and LDL cholesterol (4.30 +/- 0.71 mmol/L vs. 2.02 +/- 1.03 mmol/L, P= 0.0075), whereas HDL cholesterol was unchanged. No atherosclerosis, fatty streaks, foam cell infiltration, or inflammation were seen in any arterial samples. Brown bears tolerate elevated cholesterol levels, obesity, physical inactivity, and circulatory slow flow during hibernation without signs of -atherosclerosis. This species might serve as a reverse translational model for atherosclerosis resistance.
|
|
| 7. |
|
|
| 8. |
- Thiel, Alexandra, et al.
(författare)
-
Effects of reproduction and environmental factors on body temperature and activity patterns of wolverines
- 2019
-
Ingår i: Frontiers in Zoology. - : Springer Science and Business Media LLC. - 1742-9994. ; 16
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Mammals in the far north are exposed to extreme seasonal changes in environmental conditions, such as temperature and photoperiod, which have notable effects on animal physiology and behaviour. The wolverine (Gulo gulo) is a carnivore with a circumpolar distribution and well-adapted to extreme environmental conditions. Still, ecophysiological studies on free-ranging wolverines are lacking. In this study, we used abdominally implanted body temperature loggers in combination with GPS collars with acceleration sensors on 14 free-ranging wolverines in northern Sweden to study daily and seasonal variation in body temperature and activity patterns. We used generalized additive mixed modelling to investigate body temperature patterns over time and Lomb-Scargle periodogram analysis to analyse circadian rhythms.Results: We found that wolverines have an average core body temperature of 38.5 +/- 0.2 degrees C with a daily variation of up to 6 degrees C. Body temperature patterns varied between reproductive states. Pregnant females showed a distinct decrease in body temperature during gestation. Wolverines were active both in day and night, but displayed distinct activity peaks during crepuscular hours. However, body temperature and activity patterns changed seasonally, with a gradual change from a unimodal pattern in winter with concentrated activity during the short period of day light to a bimodal pattern in autumn with activity peaks around dusk and dawn. Wolverines were less likely to display 24-h rhythms in winter, when hours of day light are limited.Conclusions: The combination of different biologging techniques gave novel insight into the ecophysiology, activity patterns and reproductive biology of free-ranging wolverines, adding important knowledge to our understanding of animals adapted to cold environments at northern latitudes.
|
|
| 9. |
- Arnemo, Jon, et al.
(författare)
-
Brown bear (Ursus arctos; Eurasia)
- 2020
-
Ingår i: Bears of the world : ecology, conservation and management. - : Cambridge University Press. - 9781108483520 ; , s. 139-161
-
Bokkapitel (refereegranskat)abstract
|
|
| 10. |
- Arnemo, Jon
(författare)
-
Vaginal temperature and collar activity variations in relation to fecal progestagens of captive moose
- 2023
-
Ingår i: Animal Biotelemetry. - 2050-3385. ; 11
-
Tidskriftsartikel (refereegranskat)abstract
- Background Timing of reproductive events can be crucial for a species' population growth and stability. Accurate detection of reproductive phenology presents a challenge to scientists studying wild species, including moose (Alces alces). Currently, there are several established methods for monitoring reproductive activity and events in domestic ruminants, including the use of biologging devices. The main objective of this study was to determine whether female moose display a distinct thermal and activity pattern associated with luteal activity during the estrous cycle, which could be used to determine the onset of their breeding season. We deployed biologging devices and collected fecal samples from 12 captive female moose on the Kenai Peninsula, Alaska, USA to explore variation in vaginal temperature and collar activity and the relationship between these variables and fecal progestagen concentrations. Fecal samples were collected from mid-August to mid-October and analyzed using radioimmunoassay to determine the concentration of fecal progestagens to classify luteal activity.Results Captive female moose displayed an identifiable thermal pattern during the onset of luteal activity from mid-September to mid-October, associated with the initial estrous cycle of their breeding season. In contrast, we did not observe a distinct pattern in activity during this period. Recurring patterns in both vaginal temperature and activity were identified between mid-October and mid-November, however, which were likely associated with subsequent estrous cycles but not included in our fecal sampling period.Conclusions This study supports that female moose display an identifiable pattern in vaginal temperature which is associated with luteal activity of the initial estrous cycle of the breeding season. An identifiable pattern was observed for both vaginal temperature and activity registrations at the presumed timing of subsequent estrous cycle of the breeding season.
|
|
