Table of Contents
INSIDE JEB
COMMENTARIES
- Ammonia excretion in aquatic invertebrates: new insights and questions
Summary: This Commentary discusses the ammonia excretion strategies of invertebrates inhabiting a variety of different aquatic environments as well as the roles of excretory proteins in acid–base homeostasis.
- The utility of transcriptomics in fish conservation
Summary: Transcriptomic assessments, through functional analyses and the determination of negative impact thresholds, allow for a broad understanding of the mechanisms that regulate an organism's ability to respond to environmental change.
SHORT COMMUNICATIONS
- Map-like navigation from distances exceeding routine movements in the three-striped poison frog (Ameerega trivittata)
Summary: Three-striped poison frogs (Ameerega trivittata) can navigate home via a direct path from areas exceeding the range of their routine movements.
- Cognitive skills of common shrews (Sorex araneus) vary with seasonal changes in skull size and brain mass
Summary: Common shrews reduce their brain mass by 21% in winter, likely to cope with seasonal fluctuations in resources, and then regrow it by 17% the following spring, but spatial learning task experiments suggest they do so at the cost of a reduced cognitive ability in winter.
METHODS AND TECHNIQUES
- Determining forward speed from accelerometer jiggle in aquatic environments
Summary: Aquatic animal speed correlates exponentially with high-frequency accelerometer motion in underwater animal-attached devices, and the quantification of this motion can be used as a speed metric.
RESEARCH ARTICLES
- Myosin phosphorylation potentiates steady-state work output without altering contractile economy of mouse fast skeletal muscles
Summary: Myosin regulatory light chain phosphorylation potentiates dynamic contractile function of mouse fast skeletal muscles in vitro without decreasing contractile economy.
- Myosin phosphorylation improves contractile economy of mouse fast skeletal muscle during staircase potentiation
Summary: Myosin regulatory light chain phosphorylation increases the contractile economy (mechanical output:metabolic input) of wild-type mouse fast muscle compared with muscles devoid of the enzyme responsible for regulatory light chain phosphorylation.
- Lean, mean, lipolytic machines: lipid mobilization in rainbow trout during graded swimming
Summary: Rainbow trout behave like lipolytic machines that constantly mobilize lipid reserves in excess of energy requirements. High baseline lipolytic rates are not modulated by exercise, even when metabolic rate triples.
- Hormesis-like effect of mild larval crowding on thermotolerance in Drosophila flies
Summary: Mild crowding improves thermotolerance of Drosophila melanogaster larvae through potential hormetic mechanisms triggered by exposure to metabolic waste.
- Integration of celestial compass cues in the central complex of the locust brain
Highlighted Article: Polarization-sensitive neurons of the locust central complex show azimuth-dependent responses to unpolarized light spots, suggesting that direct sunlight supports the sky polarization compass in this brain area.
- Flexibility of feeding movements in pigs: effects of changes in food toughness and stiffness on the timing of jaw movements
Summary: In pigs, changes in food toughness impact chewing cycle duration and thus chewing frequency whereas changes in food stiffness alter phase duration within each cycle, with little effect on cycle duration.
- Movements of vastly different performance have similar underlying muscle physiology
Summary: Contractile properties and temperature effects are similar in tongue muscles from salamander species with different tongue-projection performance and mechanism (muscle power versus elastic recoil).
- Elucidating mechanisms for insect body size: partial support for the oxygen-dependent induction of moulting hypothesis
Summary: During a single larval instar, moths accumulated less and more mass before moulting under experimentally decreased and increased oxygen partial pressure, respectively, emphasising the role of oxygen in moult induction.
- Swim and fly: escape strategy in neustonic and planktonic copepods
Summary: New analysis supported by high-speed videos explains how some copepods can perform out-of-water escape jumps when aided by well-timed kicks when penetrating the surface.
- Protein synthesis is lowered by 4EBP1 and eIF2-α signaling while protein degradation may be maintained in fasting, hypoxic Amazonian cichlids Astronotus ocellatus
Summary: Hypoxia causes a decrease in metabolic rate, which is supported in part by a decrease in protein synthesis, and regulated by cell signaling pathways.
- Taking a goal-centred dynamic snapshot as a possibility for local homing in initially naïve bumblebees
Summary: Characteristics of initial outbound flights of bumblebees lead to a hypothesis how bumblebees use information gained in the close vicinity of their inconspicuous nest hole to return to their home location.
- Metabolome dynamics of diapause in the butterfly Pieris napi: distinguishing maintenance, termination and post-diapause phases
Highlighted Article: Diapause in a temperate butterfly is associated with a highly dynamic metabolome, and its termination, once initiated by cold, is associated with temperature-independent changes in profiles of several key metabolites.
- Too hard to swallow: a secret secondary defence of an aposematic insect
Highlighted Article: The hardness of aposematic weevils functions as an adaptive secondary defence against predator lizards, supporting Wallace's hypothesis of aposematism.
- Mechanisms for the functional differentiation of the propulsive and braking roles of the forelimbs and hindlimbs during quadrupedal walking in primates and felines
Summary: Theoretical models and empirical results reveal that functional differentiation of the limbs of quadrupeds in terms of net braking and propulsive roles is driven, in part, by the relative position of the limb point of contact relative to the center of mass.
- Odor source localization in complex visual environments by fruit flies
Summary: Fruit flies pinpoint the precise location of an odor source by integrating information derived from their visual and olfactory modalities, in both moving and still air.
- Multimodal sensorimotor system in unicellular zoospores of a fungus
Summary: The ability to respond to light and/or chemical gradients varies between Allomyces zoospores, a new model for sensory evolution; A. arbusculus behavior represents a multimodal, sensorimotor system in unicellular fungi.
- Evaluating the triplet hypothesis during rhythmic mastication in primates
Summary: The prevalence of the jaw elevator triplet motor pattern during mastication is established in five different primate species.
This issue
Other journals from The Company of Biologists
Editors’ choice – How pit vipers see (infra)red
Image credit: Tobias Kohl
Tobias Kohl and colleagues reveal that pit vipers track the front of a moving thermal image when processing infrared signals sent from the pit organs in a region of the brain known as the nucleus of the lateral descending trigeminal tract.
Featured article – Tails guard against voracious insects with curtain of breeze
Image credit: Marguerite Matherne and David Hu
Why animals swish their tails to guard against flies was a mystery until Marguerite Matherne, David Hu and a team from the Georgia Institute of Technology began analysing the motions of a wide range of animal tails and discovered that the swinging appendages generate a breeze that is sufficient to waft away irritating insects.
Review – Invertebrate serotonin receptors: a molecular perspective on classification and pharmacology
Many 5-HT receptors have been characterized at the molecular level in diverse species. Ann Jane Tierney considers 5-HT receptors in invertebrates, addressing how to classify and name these heterologously expressed receptors and comparing their pharmacological properties.
Featured article – Signalling cocktail secures octopus mum's fate
Image credit: Yan Wang
Motherhood is a fatal commitment for female octopuses, who fast as they tend their developing brood of eggs, then die just as the eggs hatch. Over 40 years ago, this selfless sacrifice was shown to be driven by the optic gland, buried deep in the female octopus brain. Now, Yan Wang and Clifton Ragsdale describe how a cocktail of signalling molecules coordinating various physiological processes is responsible for the new mother’s demise.
Meet the team
Are you going to the 2018 APS Comparative Physiology meeting in October? This meeting is supported by JEB and several of our Editors will be there - drop by the JEB exhibition stand (Booth #4) and say hello!
preLights – Antlions are sensitive to subnanometer amplitude vibrations carried by sand substrates
James Foster highlights a preprint from Vincent Lorent and co-workers revealing that antlion larvae hiding in their sand pits detect sand vibrations just a fraction of a nanometer in size. These vibrations inform the antlion of an approaching ant, and they respond by throwing sand to prevent prey from escaping their sand pits.