Stalling out chromatin machinery-Oncohistone mutation disrupts heterochromatin memory.

In this issue, Sinha et al. use cellular chromatin reporter assays along with CRISPR gene editing to reveal that the histone H3.3K36M oncohistone mutation disrupts epigenetic memory and stability of H3K9me3 domains by blocking transitions into a stably repressed state.

Divergent visual ecology of Drosophila species drives object-tracking strategies matched to landscape sparsity.

Maintaining stable gaze while tracking moving objects is commonplace across animal taxa, yet how diverse ecological needs impact these processes is poorly understood. During flight, the fruit-eating fly Drosophila melanogaster maintains course by making smooth steering adjustments to fixate the image of the distant visual background on the retina, while executing body saccades to investigate nearby objects such as food sources. Cactophilic Drosophila mojavensis live where there is no canopy; rather, the flora forming visual "background" and "objects" are one and the same.

Chemical Epigenetic Regulation of Adeno-Associated Virus Delivered Transgenes.

Adeno-associated virus (AAV) is a powerful gene therapy vector that has been used in several FDA-approved therapies as well as in multiple clinical trials. This vector has high therapeutic versatility with the ability to deliver genetic payloads to a variety of human tissue types, yet there is currently a lack of transgene expression control once the virus is administered. There are also times when transgene expression is too low for the desired therapeutic outcome, necessitating high viral dose administration resulting in possible immunological complications.

Dehydrated track a water plume in tethered flight.

Perception of sensory stimuli can be modulated by changes in internal state to drive contextually appropriate behavior. For example, dehydration is a threat to terrestrial animals, especially to due to their large surface area to volume ratio, particularly under the energy demands of flight. While hydrated avoid water cues, while walking, dehydration leads to water-seeking behavior.

Acuity and summation strategies differ in vinegar and desert fruit flies.

An animal's vision depends on terrain features that limit the amount and distribution of available light. Approximately 10,000 years ago, vinegar flies () transitioned from a single plant specialist into a cosmopolitan generalist. Much earlier, desert flies () colonized the New World, specializing on rotting cactuses in southwest North America.

Spatio-temporal Dynamics in Animal Communication: A Special Issue Arising from a Unique Workshop-Symposium Model.

Investigating how animals navigate space and time is key to understanding communication. Small differences in spatial positioning or timing can mean the difference between a message received and a missed connection. However, these spatio-temporal dynamics are often overlooked or are subject to simplifying assumptions in investigations of animal signaling.

Internal State: Dynamic, Interconnected Communication Loops Distributed Across Body, Brain, and Time.

Internal state profoundly alters perception and behavior. For example, a starved fly may approach and consume foods that it would otherwise find undesirable. A socially engaged newt may remain engaged in the presence of a predator, whereas a solitary newt would otherwise attempt to escape.

Diversity of visuomotor reflexes in two Drosophila species.

For adaptive behavior, an organism must identify and assign subjective value to salient sensory information, but what stimuli are salient could change depending upon the local features of the environment. Insects such as fruit flies (Drosophila), for example, rely on olfactory cues to locate food and oviposition sites. But not all Drosophila species find the same stimuli to be salient: for example, four geographically isolated populations of Drosophila mojavensis, which feed and oviposit on necrotic cacti, show olfactory-driven behavioral preferences for host cacti specific to the local environment of each population [1,2].

Group behavior: social context modulates behavioral responses to sensory stimuli.

A new study reveals an unanticipated role for social context in driving group behavior of a solitary species to a sensory stimulus and is mediated by mechanosensory neurons signaling touch interactions among individuals.

Olfactory neuromodulation of motion vision circuitry in Drosophila.

It is well established that perception is largely multisensory; often served by modalities such as touch, vision, and hearing that detect stimuli emanating from a common point in space; and processed by brain tissue maps that are spatially aligned. However, the neural interactions among modalities that share no spatial stimulus domain yet are essential for robust perception within noisy environments remain uncharacterized. Drosophila melanogaster makes its living navigating food odor plumes.

Drosophila tracks carbon dioxide in flight.

Carbon dioxide (CO(2)) elicits an attractive host-seeking response from mosquitos yet is innately aversive to Drosophila melanogaster despite being a plentiful byproduct of attractive fermenting food sources. Prior studies used walking flies exclusively, yet adults track distant food sources on the wing. Here we show that a fly tethered within a magnetic field allowing free rotation about the yaw axis actively seeks a narrow CO(2) plume during flight.

Flies dynamically anti-track, rather than ballistically escape, aversive odor during flight.

Tracking distant odor sources is crucial to foraging, courtship and reproductive success for many animals including fish, flies and birds. Upon encountering a chemical plume in flight, Drosophila melanogaster integrates the spatial intensity gradient and temporal fluctuations over the two antennae, while simultaneously reducing the amplitude and frequency of rapid steering maneuvers, stabilizing the flight vector. There are infinite escape vectors away from a noxious source, in contrast to a single best tracking vector towards an attractive source.

Regulation of response properties and operating range of the AFD thermosensory neurons by cGMP signaling.

Background: The neuronal mechanisms that encode specific stimulus features in order to elicit defined behavioral responses are poorly understood. C. elegans forms a memory of its cultivation temperature (T(c)) and exhibits distinct behaviors in different temperature ranges relative to T(c).

Genome-wide analysis of light- and temperature-entrained circadian transcripts in Caenorhabditis elegans.

Most organisms have an endogenous circadian clock that is synchronized to environmental signals such as light and temperature. Although circadian rhythms have been described in the nematode Caenorhabditis elegans at the behavioral level, these rhythms appear to be relatively non-robust. Moreover, in contrast to other animal models, no circadian transcriptional rhythms have been identified.

An olfactory neuron responds stochastically to temperature and modulates Caenorhabditis elegans thermotactic behavior.

Caenorhabditis elegans navigates thermal gradients by using a behavioral strategy that is regulated by a memory of its cultivation temperature (T(c)). At temperatures above or around the T(c), animals respond to temperature changes by modulating the rate of stochastic reorientation events. The bilateral AFD neurons have been implicated as thermosensory neurons, but additional thermosensory neurons are also predicted to play a role in regulating thermotactic behaviors.

A diacylglycerol kinase modulates long-term thermotactic behavioral plasticity in C. elegans.

A memory of prior thermal experience governs Caenorhabditis elegans thermotactic behavior. On a spatial thermal gradient, C. elegans tracks isotherms near a remembered temperature we call the thermotactic set-point (T(S)).