Respiratory and hematological physiology of day 15 chicken embryos (Gallus gallus domesticus) during water submergence and air recovery: Implications for bird embryos experiencing nest inundation.

Bird nests of coastal or inland breeding birds can temporarily flood during high tides or storms. However, respiratory physiological disruption of such water submersion and implications for post-submergence survival are poorly understood. We hypothesized that respiratory physiological disturbances caused by submersion would be rapidly corrected following return to normal gas exchange across the eggshell, thus explaining survival of nest inundation in the field.

Development and sex affect respiratory responses to temperature and dissolved oxygen in the air-breathing fishes Betta splendens and Trichopodus trichopterus.

Ventilation frequencies of the gills (f) and the air-breathing organ (f) were measured in juveniles and adults of the air-breathing betta (Betta splendens) and the blue gourami (Trichopodus trichopterus) in response to temperature and hypoxia. Ventilatory rates were evaluated after 1 h of exposure to 27 °C (control), 23 and 31 °C (PO = 21.0 kPa), after acute temperature changes (ATC) from 23 to 27, and 27 to 31 °C, and under progressive hypoxia (PH; PO =  ~ 21 to 2.

Beta-adrenergic blockade via atenolol negatively affects body and heart mass and renal morphology in the developing chicken (Gallus Gallus Domesticus).

Atenolol is a widely prescribed β-cardioselective blocker. We studied atenolol effects on cardiac and renal development in day 18 (D18) chicken embryos. Embryos were dosed with atenolol (3 μg atenolol/g estimated embryo mass) for three days during one of the mesonephric kidney stage (D7-D9), mesonephric-metanephric stage (D11-D13), or metanephric stage (D15-D17), and then sampled on D18.

The role of cognition as a factor regulating the diving responses of animals, including humans.

The dive response involves three main components - breath holding, reduced heart rate and increased peripheral vasoconstriction - and is ubiquitous during forced dives in air-breathing vertebrates; however, numerous studies in free-diving animals have shown that the heart rate response to diving varies considerably in a manner that suggests cognitive control. Furthermore, studies on free-diving animals and controlled experiments in trained animals both indicate that the dive response can be conditioned, such that the reduction in heart rate begins before submergence and the extent of the reduction is set early in the dive. In addition, numerous species also experience an increase in heart rate and blood flow during ascent at the end of a dive, a phenomenon commonly called 'ascent tachycardia'.

Short communication: Baroreflex function in embryonic emus (Dromiceius novaehollandiae).

The baroreflex involves cardiovascular homeostatic mechanisms that buffer the system against acute deviations in arterial blood pressure. It is comprised of the cardiac limb which involves adjustments in heart rate and the peripheral limb which involves adjustments in vascular resistance. This negative feedback loop mechanism has been investigated in numerous species of adult vertebrates, however our understanding of the maturation and functional importance of the reflex in developing animals remains poorly understood.

Temperature and hypoxia trigger developmental phenotypic plasticity of cardiorespiratory physiology and growth in the parthenogenetic marbled crayfish, Procambarus virginalis Lyko, 2017.

Attempting to differentiate phenotypic variation caused by environmentally-induced alterations in gene expression from that caused by actual allelic differences can be experimentally difficult. Environmental variables must be carefully controlled and then interindividual genetic differences ruled out as sources of phenotypic variation. We investigated phenotypic variability of cardiorespiratory physiology as well as biometric traits in the parthenogenetically-reproducing marbled crayfish Procambarus virginalis Lyko, 2017, all offspring being genetically identical clones.

"Bet hedging" against climate change in developing and adult animals: roles for stochastic gene expression, phenotypic plasticity, epigenetic inheritance and adaptation.

Animals from embryos to adults experiencing stress from climate change have numerous mechanisms available for enhancing their long-term survival. In this review we consider these options, and how viable they are in a world increasingly experiencing extreme weather associated with climate change. A deeply understood mechanism involves natural selection, leading to evolution of new adaptations that help cope with extreme and stochastic weather events associated with climate change.

Dietary crude oil exposure during sex differentiation skewed adult sex ratio towards males in the zebrafish.

Dietary crude oil exposure has detrimental morpho-physiological effects in fishes, including endocrine disruption. However, little is known about how it influences sex differentiation and its potential for skewing sex ratios of populations. Appropriate sex ratio is important for maintaining effective population size and structure.

Zebrafish (Danio rerio) shoaling in light and dark conditions involves a complex interplay between vision and lateral line.

We know little about how - or even if in some species - fish shoal in darkness. We hypothesized that 'dark shoaling' occurs in zebrafish and therefore must depend upon lateral line sensory input. Shoaling in groups of five adult zebrafish was analyzed with motion tracking software.

Insufficient reporting of experimental variables as a cause for nonreproducibility in animal physiology? A case study.

Nonreproducibility in scientific investigations has been explained by inadequately reporting methodology, honest error, and even misconduct. We hypothesized that, within the field of animal physiology, the most parsimonious explanation for nonreproducibility is inadequate reporting of key methodological details. We further hypothesized that implementation of relatively recently released reporting guidelines has positively impacted journal article quality, as measured by completeness of the methodology descriptions.

Physiological Regulation of Growth, Hematology and Blood Gases in Chicken Embryos in Response to Low and High Incubation Humidity.

Variations from a relative humidity (RH) of ∼50-60% can unfavorably alter chicken embryo development, but little is known of whether the embryo can mitigate these effects through physiological regulation. We examined effects of Low RH (25-35%), and High RH (85-93%) compared to Control RH (50-60%) on hatchability, embryonic growth, hematology and blood gases and pH. Mean hatchability was not affected by RH.

Metabolic responses to crude oil during early life stages reveal critical developmental windows in the zebrafish (Danio rerio).

Morphological effects of crude oil exposure on early development in fishes have been well documented, but crude oil's metabolic effects and when in early development these effects might be most prominent remains unclear. We hypothesized that zebrafish (Danio rerio) exposed to crude oil as a high energy water accommodated fraction (HEWAF) would show increased routine oxygen consumption (ṀO) and critical oxygen tension (P) and this effect would be dependent upon day of HEWAF exposure, revealing critical windows of development for exposure effects. Zebrafish were exposed to 0%, 10%, 25%, 50% or 100% HEWAF for 24 h during one of the first six days post-fertilization (dpf).

Metabolic cost of development, regeneration, and reproduction in the planarian Schmidtea mediterranea.

Planaria are known for their ability to completely regenerate upon fissioning or experimental amputation. Yet, metabolic costs of regeneration have not been directly measured in planaria. Our goal was to establish the relationships between oxygen consumption (V̇O2), regeneration, and reproductive mode for asexual and sexual strains of Schmidtea mediterranea.

Form and Function of the Vertebrate and Invertebrate Blood-Brain Barriers.

The need to protect neural tissue from toxins or other substances is as old as neural tissue itself. Early recognition of this need has led to more than a century of investigation of the blood-brain barrier (BBB). Many aspects of this important neuroprotective barrier have now been well established, including its cellular architecture and barrier and transport functions.

Morphological and cardiac alterations after crude oil exposure in the early-life stages of the tropical gar (Atractosteus tropicus).

Fish development can be affected by environmental pollutants such as crude oil (anthropogenic or natural sources), causing alterations especially in cardiac function and morphology. Most such studies have focused on saltwater species, whereas studies in freshwater fishes are scant. The objective of the current study was to evaluate the effects of crude oil exposure (as 0, 5, 10, 15, or 20% high-energy water accommodated fractions, HEWAF) on cardiac function and edema formation during two early periods of development (embryo and eleuteroembryo, 48 h each) individually using the tropical gar Atractosteus tropicus as a model.

Beyond the Chicken: Alternative Avian Models for Developmental Physiological Research.

Biomedical research focusing on physiological, morphological, behavioral, and other aspects of development has long depended upon the chicken () as a key animal model that is presumed to be typical of birds and generally applicable to mammals. Yet, the modern chicken in its many forms is the result of artificial selection more intense than almost any other domesticated animal. A consequence of great variation in genotype and phenotype is that some breeds have inherent aberrant physiological and morphological traits that may show up relatively early in development (e.

Hypoxia- and hyperoxia-related gene expression dynamics during developmental critical windows of the tropical gar Atractosteus tropicus.

Aquatic hypoxia is both a naturally-occurring and anthropogenically-generated event. Fish species have evolved different adaptations to cope with hypoxic environments, including gill modifications and air breathing. However, little is known about the molecular mechanisms involved in the respiration of embryonic and larval fishes during critical windows of development.

Embryotoxicity and Physiological Compensation in Chicken Embryos Exposed to Crude Oil.

Terrestrial, marine, or aquatic oil spills can directly or indirectly contaminate bird eggs. We hypothesized that chicken embryos exposed to crude oil can physiologically compensate to mitigate the potentially toxic effect of lower doses of oil. Embryos exposed to 0, 1, 3, or 5 µL of oil on embryonic days 4 and 10 were initially analyzed for mortality.

Dietary Exposure to Low Levels of Crude Oil Affects Physiological and Morphological Phenotype in Adults and Their Eggs and Hatchlings of the King Quail ().

Despite the current knowledge of the devastating effects of external exposure to crude oil on animal mortality, the study of developmental, transgenerational effects of such exposure has received little attention. We used the king quail as an animal model to determine if chronic dietary exposure to crude oil in a parental population would affect morpho-physiological phenotypic variables in their immediate offspring generation. Adult quail were separated into three groups: (1) Control, and two experimental groups dietarily exposed for at least 3 weeks to (2) Low (800 PAH ng/g food), or (3) High (2,400 PAH ng/g food) levels of crude oil.