Hypothalamic remodeling of thyroid hormone signaling during hibernation in the arctic ground squirrel DOI Creative Commons
Helen E. Chmura, Cassandra Duncan, Ben Saer

et al.

Communications Biology, Journal Year: 2022, Volume and Issue: 5(1)

Published: May 23, 2022

Abstract Hibernation involves prolonged intervals of profound metabolic suppression periodically interrupted by brief arousals to euthermy, the function which is unknown. Annual cycles in mammals are timed a photoperiodically-regulated thyroid-hormone-dependent mechanism hypothalamic tanycytes, driven thyrotropin (TSH) pars tuberalis (PT), regulates local TH-converting deiodinases and triggers remodeling neuroendocrine pathways. We demonstrate that over course hibernation continuous darkness, arctic ground squirrels ( Urocitellus parryii ) up-regulate retrograde TSH/Deiodinase/TH pathway, remodel activate reproductive axis. Forcing premature termination warming animals induced deiodinase expression accumulation secretory granules PT thyrotrophs pituitary gonadotrophs, but did not further suggest periodic may allow for transient activation thyroid hormone signaling, cellular remodeling, re-programming brain circuits preparation short Arctic summer.

Language: Английский

Squamate metabolic rates decrease in winter beyond the effect of temperature DOI Creative Commons
Shahar Dubiner, Simon Jamison, Shai Meiri

et al.

Journal of Animal Ecology, Journal Year: 2023, Volume and Issue: 92(11), P. 2163 - 2174

Published: Aug. 26, 2023

The reptilian form of hibernation (brumation) is much less studied than its mammalian and insect equivalents. Hibernation brumation share some basic features but may differ in others. Evidence for hypometabolism brumating reptiles beyond the effect temperature sporadic often ignored. We calculated standard metabolic rates (SMR, oxygen uptake during inactivity), winter and/or summer, 156 individuals representing 59 species Israeli squamates across all 17 local families. For 32 species, we measured same both seasons. gas exchange continuously a dark chamber, under average January high low temperatures (20°C 12°C), daytime nighttime. examined how SMR changes with season, biome, body size, time day, using phylogenetic mixed models. Metabolic increased at sunrise diurnal despite no light or other external cues, while nocturnal did not increase. Cathemeral shifted from diurnal-like diel pattern to nocturnal-like summer. Regardless Mediterranean SMRs were 30% higher similar-sized desert species. Summer together scaled size an exponent 0.84 dropped 0.71 brumation. Individuals seasons decreased their between summer by 47%, on average, 20°C 70% 12°C. Q10 was 1.75 times possibly indicating active suppression processes cold temperatures. Our results challenge commonly held perception that squamate physiology mainly shaped temperature, little role intrinsic regulation. patterns describe indicate seasonal, geographic factors can trigger remarkable shifts metabolism

Language: Английский

Citations

15
Variation in Thermal Sensitivity of Diapause Development among Individuals and over Time Predicts Life History Timing in a Univoltine Insect DOI
Jantina Toxopeus,

Edwina Dowle,

Lalitya Andaloori

et al.

The American Naturalist, Journal Year: 2024, Volume and Issue: 203(6), P. E200 - E217

Published: Jan. 19, 2024

Language: Английский

Citations

5
Cold tolerance and diapause within and across trophic levels: Endoparasitic wasps and their fly host have similar phenotypes DOI

Trinity McIntyre,

Lalitya Andaloori,

Glen R. Hood

et al.

Journal of Insect Physiology, Journal Year: 2023, Volume and Issue: 146, P. 104501 - 104501

Published: March 13, 2023

Language: Английский

Citations

12
The pine bark beetle Ips acuminatus: an ecological perspective on life-history traits promoting outbreaks DOI Creative Commons
Eva Papek, Elisabeth Ritzer, Peter H. W. Biedermann

et al.

Journal of Pest Science, Journal Year: 2024, Volume and Issue: 97(3), P. 1093 - 1122

Published: March 16, 2024

Abstract The bark beetle Ips acuminatus is an important pest in pine-dominated forests of Eurasia. Recently, the frequency I. outbreaks and mortality host trees have increased, most likely as a result climate change-related alterations environmental conditions. Therefore, detailed information on species’ natural history essential to understand its potential damage apply sustainable management measures. We provide comprehensive overview life , focusing traits that might explain ability cause tree mortality. review importance for European forestry, outbreak behavior, plant usage, reproductive biology, temperature-dependent development, diapause overwintering interactions with fungi, bacteria, nematodes other arthropods. Interestingly, has strong nutritional dependency fungus Ophiostoma macrosporum underlined by presence prominent oral mycetangium, spore-carrying organ, females, which not known species. Moreover, can reproduce sexually asexually (pseudogamy). Additionally, evolutionary past provides valuable insights into origin certain traits. present phylogeny genus examine selected life-history context. Together sister species chinensis, forms separate clade within Ips. ancestor beetles originated about 20 million years ago was pine-colonizing inhabiting Holarctic. Finally, open fields research are identified guide future work this ecologically economically pine beetle.

Language: Английский

Citations

4
Obligate diapause and its termination shape the life-cycle seasonality of an Antarctic insect DOI Creative Commons
Mizuki Yoshida, Peter Convey, Scott A. L. Hayward

et al.

Scientific Reports, Journal Year: 2025, Volume and Issue: 15(1)

Published: Feb. 12, 2025

Language: Английский

Citations

0
Simulated climate warming scenarios lead to earlier emergence and increased weight loss but have no effect on overwintering survival in solitary bees DOI Creative Commons
Jannik S. Möllmann,

Liv Lörchner,

Dorothee Hodapp

et al.

Journal of Insect Physiology, Journal Year: 2025, Volume and Issue: unknown, P. 104811 - 104811

Published: April 1, 2025

Language: Английский

Citations

0
Surviving winter: Physiological regulation of energy balance in a temperate ectotherm entering and exiting brumation DOI
Kaitlyn G. Holden, Eric J. Gangloff,

Evangelina Gomez-Mancillas

et al.

General and Comparative Endocrinology, Journal Year: 2021, Volume and Issue: 307, P. 113758 - 113758

Published: March 24, 2021

Language: Английский

Citations

26
Snow modulates winter energy use and cold exposure across an elevation gradient in a montane ectotherm DOI Creative Commons
Kevin T. Roberts, Nathan E. Rank, Elizabeth P. Dahlhoff

et al.

Global Change Biology, Journal Year: 2021, Volume and Issue: 27(23), P. 6103 - 6116

Published: Oct. 4, 2021

Snow insulates the soil from air temperature, decreasing winter cold stress and altering energy use for organisms that overwinter in soil. As climate change alters snowpack temperatures, it is critical to account role of snow modulating vulnerability change. Along elevational gradients snowy mountains, cover increases but temperature decreases, unknown how these opposing impact performance fitness overwintering We developed experimentally validated ecophysiological models over past decade montane leaf beetle Chrysomela aeneicollis, along five replicated transects Sierra Nevada mountains California. Cold peaks at mid-elevations, while high elevations are buffered by persistent cover, even dry years. While protective against cold, beetles, particularly low elevations, potentially leading mortality or energetic tradeoffs. Declining will predominantly mid-elevation populations increasing exposure, elevation habitats may provide refugia as drier winters become more common.

Language: Английский

Citations

26
Seasonal remodeling of visceral organs in the invasive desert gecko Tarentola annularis DOI Creative Commons
Shahar Dubiner, Shai Meiri, Eran Levin

et al.

Integrative Zoology, Journal Year: 2024, Volume and Issue: 19(6), P. 1047 - 1056

Published: Feb. 13, 2024

In winter, many reptiles have a period of inactivity ("brumation"). During brumation there is no energetic intake, therefore would be an advantage to reducing expenditure. The size energetically costly organs, major determinant metabolic rate, known flexible in tetrapods. Seasonal plasticity organ could serve as both energy-saving mechanism and source nutrients for brumating reptiles. We studied population invasive gecko, Tarentola annularis, test seasonal changes activity, mass various organs. observed was December-February. Standard rates during the activity season were 1.85 times higher than individuals. This may attributed decreased winter: heart by 37%, stomach 25%, liver 69%. Interestingly, testes increased 100% likely preparation breeding season, suggesting that males prioritize over other functions upon return activity. kidneys lungs remained constant. Organ atrophy occurred only after geckos reduced their so we hypothesize response (rather anticipation of) cold winter temperatures associated fasting. Degradation visceral organs can maintain energy demands low supply, catabolism protein from these water brumation. These findings bring us closer mechanistic understanding reptiles' physiological adaptations environmental changes.

Language: Английский

Citations

3
Safe Periods and Safe Activities: Two Phenological Responses to Mortality DOI Creative Commons
Théo Constant, F. Stephen Dobson, Sylvain Giroud

et al.

Ecology and Evolution, Journal Year: 2025, Volume and Issue: 15(2)

Published: Feb. 1, 2025

ABSTRACT Phenology is often thought to evolve mainly in response food availability, yet recent studies have focused on predation. Predation may explain apparent mismatches between phenology and resources. One type of phenological predation involves shifting from a period high low (i.e., safe‐period strategy). This strategy presupposes variation over time due environmental factors such as the number or diversity predators. varies not only but also among different activities like reproduction dormancy. Alternative involve alternative behavioral physiological states, locations where they take place influencing risk. Phenological responses risk activity safer one, resulting increased survival «safe‐activity» theoretically under conditions associated with constant time, assumes activities. Safe‐period safe‐activity strategies are mutually exclusive, assume for their evolution. On basis literature review, our goal was to: (1) propose classification according evolutionary context, including mean population interindividual differences (degree synchrony); (2) show how these two lack support idea that responds primarily availability; (3) several approaches testing influence phenology. Our review highlights relevance studying multiple scales, thereby integrating interspecific interactions (communities scales) (annual scale), synchronicity pace‐of‐life (inter‐individual scale).

Language: Английский

Citations

0