Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Chronic immune challenge is detrimental to female survival, feeding behavior, and reproduction in the field cricket Gryllus assimilis (Fabricius, 1775)
In this study, employing a widely used method to challenge the insect immune system (nylon implant), we assessed the effects of mounting a chronic immune response simulating three successive immune assaults on survival and reproduction of mated females ofGryllus assimilis. We also verified feeding behavior following an implantation, which can be important in explaining trade-off dynamics in terms of energy acquisition. For this, three experimental groups were designed (Control, Sham, and Implant) with oviposition rates, egg morphometry, and nymph vigour observed over 3  weeks, at which ovarian mass and unlaid eggs were qu...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - February 23, 2022 Category: Physiology Source Type: research

Lactate inhibits naked mole-rat cardiac mitochondrial respiration
AbstractIn aerobic conditions, the proton-motive force drives oxidative phosphorylation (OXPHOS) and the conversion of ADP to ATP. In hypoxic environments, OXPHOS is impaired, resulting in energy shortfalls and the accumulation of protons and lactate. This results in cellular acidification, which may impact the activity and/or integrity of mitochondrial enzymes and in turn negatively impact mitochondrial respiration and thus aerobic ATP production. Naked mole-rats (NMRs) are among the most hypoxia-tolerant mammals and putatively experience intermittent hypoxia in their underground burrows. However, if and how NMR cardiac m...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - February 18, 2022 Category: Physiology Source Type: research

Seasonal patterns in behavior and glucocorticoid secretion of a specialist Holarctic tree squirrel (Sciurus aberti)
AbstractSeasonally breeding mammals must make constant adjustments in behavior and physiology to manage energetic trade-offs between survival and reproduction. Despite encountering high levels of climate and resource variability across the year, specialist Abert ’s squirrels (Sciurus aberti), lack the capacity to express hibernation or pronounced morphological adaptations to seasonality. Using accelerometer and GPS devices, we assessed how abiotic environmental factors, reproduction, and resource abundance influenced levels of activity and daily range size in a rural and food-supplemented suburban population of squirrels...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - February 14, 2022 Category: Physiology Source Type: research

A review of the effects of incubation conditions on hatchling phenotypes in non-squamate reptiles
AbstractDeveloping embryos of oviparous reptiles show substantial plasticity in their responses to environmental conditions during incubation, which can include altered sex ratios, morphology, locomotor performance and hatching success. While recent research and reviews have focused on temperature during incubation, emerging evidence suggests other environmental variables are also important in determining hatchling phenotypes. Understanding how the external environment influences development is important for species management and requires identifying how environmental variables exert their effects individually, and how th...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - February 10, 2022 Category: Physiology Source Type: research

Structure and permeability of the egg capsule of the placental Australian sharpnose shark, Rhizoprionodon taylori
AbstractShark placentae are derived from modifications to the fetal yolk sac and the maternal uterine mucosa. In almost all placental sharks, embryonic development occurs in an egg capsule that remains intact for the entire pregnancy, separating the fetal tissues from the maternal tissues at the placental interface. Here, we investigate the structure and permeability of the egg capsules that surround developing embryos of the placental Australian sharpnose shark (Rhizoprionodon taylori) during late pregnancy. The egg capsule is an acellular fibrous structure that is 0.42  ± 0.04 μm thick at the placental interface b...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - February 4, 2022 Category: Physiology Source Type: research

De novo transcriptome assembly of the midgut glands of herbivorous land crabs, Chiromantes haematocheir, and identification of laccase genes involved in lignin degradation
In this study, we performed RNA-seq analysis to detect biomass-degrading enzymes. A de novo transcriptome assembly in the midgut glands of molting and non-moltingC. haematocheir crabs was constructed using RNA sequencing. Illumina sequencing generated 44,937,002 and 44,394,310 reads from the two midgut glands. In total, 178,710 contigs with an average length of 750  bp and an N50 value of 1,235 bp were assembled, of which 37,890 contigs were annotated using BLASTx search against the NCBI database. We identified 22 contigs (11 genes) belonging to the laccase family and 44 contigs (22 genes) belonging to the peroxidase fam...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - January 28, 2022 Category: Physiology Source Type: research

Comparative transcriptomics reveal tissue level specialization towards diet in prickleback fishes
AbstractBeyond a few obvious examples (e.g., gut length, amylase activity), digestive and metabolic specializations towards diet remain elusive in fishes. Thus, we compared gut length, δ13C and δ15N signatures of the liver, and expressed genes in the intestine and liver of wild-caught individuals of four closely-related, sympatric prickleback species (family Stichaeidae) with different diets:Xiphister mucosus (herbivore), its sister taxonX. atropurpureus (omnivore),Phytichthys chirus (omnivore) and the carnivorousAnoplarchus purpurescens. We also measured the same parameters after feeding them carnivore or omnivore diets...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - January 25, 2022 Category: Physiology Source Type: research

Habitat aridity as a determinant of the trade-off between water conservation and evaporative heat loss in bats
AbstractThe maintenance of water balance in arid environments might represent a formidable challenge for Chiroptera, since they have high surface-to-volume ratios. In deserts, bats conserve water, for example, using daily torpor, but they also might experience episodic heat bouts, when they may need to increase total evaporative water loss (TEWL) to thermoregulate. We hypothesized that in bats, habitat aridity and its variability determine a trade-off between water conservation and thermoregulation via evaporative means. To test this hypothesis, we collated data from the literature of 22 species of bats on TEWL, body tempe...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - January 17, 2022 Category: Physiology Source Type: research

Changing lanes: seasonal differences in cellular metabolism of adipocytes in grizzly bears (Ursus arctos horribilis)
AbstractObesity is among the most prevalent of health conditions in humans leading to a multitude of metabolic pathologies such as type 2 diabetes and hyperglycemia. However, there are many wild animals that have large seasonal cycles of fat accumulation and loss that do not result in the health consequences observed in obese humans. One example is the grizzly bear (Ursus arctos horribilis) that can have body fat content  >  40% that is then used as the energy source for hibernation. Previous in vitro studies found that hibernation season adipocytes exhibit insulin resistance and increased lipolysis. Yet, other aspe...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - January 13, 2022 Category: Physiology Source Type: research

Mitochondrial respiration in rats during hypothermia resulting from central drug administration
AbstractThe ability to induce a hypothermia resembling that of natural torpor would be greatly beneficial in medical and non-medical fields. At present, two procedures based on central nervous pharmacological manipulation have been shown to be effective in bringing core body temperature well below 30  °C in the rat, a non-hibernator: the first, based on the inhibition of a key relay in the central thermoregulatory pathway, the other, based on the activation of central adenosine A1 receptors. Although the role of mitochondria in the activation and maintenance of torpor has been extensively stud ied, no data are available ...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - January 10, 2022 Category: Physiology Source Type: research

Morphometrics and blood analytes of leatherback sea turtle hatchlings (Dermochelys coriacea) from Florida: reference intervals, temporal trends with clutch deposition date, and body size correlations
AbstractThe northwest Atlantic leatherback sea turtle (Dermochelys coriacea) population is exhibiting decreasing trends along numerous nesting beaches. Since population health and viability are inherently linked, it is important to establish species- and life-stage class-specific blood analyte reference intervals (RIs) so that effects of future disturbances on organismal health can be better understood. For hatchling leatherbacks, the objectives of this study were to (1) establish RIs for morphometrics and blood analytes; (2) evaluate correlations between hatchling morphometrics, blood analytes, and hatching success; and (...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - January 8, 2022 Category: Physiology Source Type: research

Phenotypic plasticity to chronic cold exposure in two species of Peromyscus from different environments
AbstractEffective thermoregulation is important for mammals, particularly those that remain winter-active. Adjustments in thermoregulatory capacity in response to chronic cold can improve capacities for metabolic heat production (cold-induced maximal oxygen consumption,\({\dot{\text{V}}\text{O}}_{{2}} {\text{max}}\)), minimize rates of heat loss (thermal conductance), or both. This can be challenging for animals living in chronically colder habitats where necessary resources (i.e., food, O2) for metabolic heat production are limited. Here we used lowland native white-footed mice (Peromyscus leucopus) and highland deer mice...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - January 6, 2022 Category: Physiology Source Type: research