Highlights d Early-life starvation and unrestricted feeding result in reproductive abnormalities d Maternal dietary restriction protects progeny from starvationinduced abnormalities d Maternal diet and insulin/IGF signaling affect vitellogenin oocyte provisioning d Vitellogenin oocyte provisioning affects progeny insulin/IGF signaling

The complex molecular and cellular mechanisms underlying neuronal control of animal movement are not well understood. Locomotion of Caenorhabditis elegans is mediated by a neuronal circuit that produces coordinated sinusoidal movement. Here we utilize this simple, yet elegant, behavior to show that VAV-1, a conserved guanine nucleotide exchange factor for Rho-family GTPases, negatively regulates motor circuit activity and the rate of locomotion. While vav-1 is expressed in a small subset of neurons, we find that VAV-1 function is required in a single interneuron ALA to regulate motor neuron circuit activity. Furthermore, we show by genetic and optogenetic manipulation of ALA that VAV-1 is required for the excitation and activation of this neuron. We find that ALA signaling inhibits command interneuron activity by abrogating excitatory signaling in the command interneurons that is responsible for promoting motor neuron circuit activity. Togther, our data describe a novel neuromodulatory role for VAV-1-dependent signaling in the regulation of motor circuit activity and locomotion.

Group living is widespread in the animal kingdom and recent studies into the mechanisms underlying group cohesion and behavioural synchrony have highlighted the importance of between-individual behavioural differences ('animal personality'). In group-living animals, social conformity occurs when animals compromise their own behaviour to the level of a certain behaviour displayed by another individual or a group, and the degree to which individuals conform can depend upon interindividual differences in behavioural types. Social conformity can increase group cohesion and ultimately predator avoidance and/or resource acquisition for group-living individuals. However, it remains unclear whether similar conformity effects exist in solitary species, many of which form temporary aggregations and, if so, whether changes in behaviour in the presence of conspecifics are dependent on individuals' personalities in solitary contexts. We studied the effects of social context (i.e. the presence of a conspecific) on behaviour in solitary shore crabs, using automated video tracking. Individuals differed consistently in their activity levels within and across contexts and were significantly more active in solitary than dyadic contexts. No differences in activity between same-and opposite-sex dyads were found. Crabs' activity levels were more similar

Sleep is evolutionarily conserved and required for organism homeostasis and survival. Despite this importance, the molecular and cellular mechanisms underlying sleep are not well understood. Caenorhabditis elegans exhibits sleep-like behavioral quiescence and thus provides a valuable, simple model system for the study of cellular and molecular regulators of this process. In C. elegans, epidermal growth factor receptor (EGFR) signaling is required in the neurosecretory neuron ALA to promote sleep-like behavioral quiescence after cellular stress. We describe a novel role for VAV-1, a conserved guanine nucleotide exchange factor (GEF) for Rho-family GTPases, in regulation of sleep-like behavioral quiescence. VAV-1, in a GEF-dependent manner, acts in ALA to suppress locomotion and feeding during sleep-like behavioral quiescence in response to cellular stress. Additionally, VAV-1 activity is required for EGF-induced sleep-like quiescence and normal levels of EGFR and secretory dense core vesicles in ALA. Importantly, the role of VAV-1 in promoting cellular stress-induced behavioral quiescence is vital for organism health because VAV-1 is required for normal survival after cellular stress.KEYWORDS behavioral quiescence; Caenorhabditis elegans; sleep; Vav D ESPITE being a subject of formal study for over 150 years, sleep is not clearly understood. Moreover, various explanations for the functional role of sleep have been proposed, such as allowing "recharging" of cells following high metabolic activity (Benington and Heller 1995;Tu and McKnight 2006;Scharf et al. 2008) and remodeling of synapses built during wakefulness (Tononi and Cirelli 2006). Yet sleep problems have a significant impact on human health and are a leading reason for seeking medical attention (Mahowald and Schenck 2005). Therefore, there is a great need for understanding the cellular and molecular mechanisms that regulate sleep-wake cycles.Simple model organisms such as Caenorhabditis elegans have the potential to provide valuable information regarding sleep regulation. C. elegans is known for its easily manipulated genetics, small nervous system with mapped neuronal connectivity, stereotypical behaviors, and the ability to be studied efficiently in large numbers. Numerous studies have shown that C. elegans lethargus, a restful period that occurs before each molt of the cuticle during larval development, is neuronally regulated and likely orthologous to sleep in mammals (Van Buskirk and Sternberg 2007;Raizen et al. 2008;Van Buskirk and Sternberg 2010;Choi et al. 2013;Iwanir et al. 2013;Turek et al. 2013;Cho and Sternberg 2014;Singh et al. 2014). Lethargus quiescence in C. elegans shares several characteristics with mammalian sleep: inactivity (decreased locomotion and cessation of pharyngeal pumping, or feeding), a specific posture, reduced response to aversive stimuli, and rapid reversibility (Cassada and Russell 1975;Raizen et al. 2008;Schwarz et al. 2012;Iwanir et al. 2013;Cho and Sternberg 2014). In addition, lethargus quiescence is under ...

Sheep wool cortisol as a retrospective measure of long-term HPA-axis activity and links to body mass. Domestic Animal Endocrinology