Refinement of a technique for collecting and evaluating the osmolality of haemolymph from Drosophila larvae.

Ex vivo physiological experiments using small insect models such as Drosophila larvae have become increasingly useful to address fundamental biological questions. To perform such experiments, various artificial saline solutions have been developed, but their osmolality varies significantly from one to the next. Such a variation of osmolality stems, in part, from the difficulty of determining the true value of haemolymph osmolality in Drosophila larvae.

Belly roll, a GPI-anchored Ly6 protein, regulates escape behaviors by modulating the excitability of nociceptive peptidergic interneurons.

Appropriate modulation of escape behaviors in response to potentially damaging stimuli is essential for survival. Although nociceptive circuitry has been studied, it is poorly understood how genetic contexts affect relevant escape responses. Using an unbiased genome-wide association analysis, we identified an Ly6/α-neurotoxin family protein, Belly roll (Bero), which negatively regulates nociceptive escape behavior.

Inter-organ Wingless/Ror/Akt signaling regulates nutrient-dependent hyperarborization of somatosensory neurons.

Nutrition in early life has profound effects on an organism, altering processes such as organogenesis. However, little is known about how specific nutrients affect neuronal development. Dendrites of class IV dendritic arborization neurons in larvae become more complex when the larvae are reared on a low-yeast diet compared to a high-yeast diet.

E-cadherin-dependent coordinated epithelial rotation on a two-dimensional discoidal pattern.

In vivo, cells collectively migrate in a variety of developmental and pathological contexts. Coordinated epithelial rotation represents a unique type of collective cell migrations, which has been modeled in vitro under spatially confined conditions. Although it is known that the coordinated rotation depends on intercellular interactions, the contribution of E-cadherin, a major cell-cell adhesion molecule, has not been directly addressed on two-dimensional (2D) confined substrates.

Small conductance Ca-activated K channels induce the firing pause periods during the activation of nociceptive neurons.

In larvae, Class IV sensory neurons respond to noxious thermal stimuli and provoke heat avoidance behavior. Previously, we showed that the activated neurons displayed characteristic fluctuations of firing rates, which consisted of repetitive high-frequency spike trains and subsequent pause periods, and we proposed that the firing rate fluctuations enhanced the heat avoidance (Terada et al., 2016).

Mitochondrial dysfunction induces dendritic loss via eIF2α phosphorylation.

Mitochondria are key contributors to the etiology of diseases associated with neuromuscular defects or neurodegeneration. How changes in cellular metabolism specifically impact neuronal intracellular processes and cause neuropathological events is still unclear. We here dissect the molecular mechanism by which mitochondrial dysfunction induced by Prel aberrant function mediates selective dendritic loss in class IV dendritic arborization neurons.

Nutrient-dependent increased dendritic arborization of somatosensory neurons.

Suboptimal nutrition imposes developmental constraints on infant animals, which marshal adaptive responses to eventually become mature adults. Such responses are mounted at multiple levels from systemic to cellular. At the cellular level, the underlying mechanisms of cell proliferation control have been intensively studied.

An evolutionarily conserved protein CHORD regulates scaling of dendritic arbors with body size.

Most organs scale proportionally with body size through regulation of individual cell size and/or cell number. Here we addressed how postmitotic and morphologically complex cells such as neurons scale with the body size by using the dendritic arbor of one Drosophila sensory neuron as an assay system. In small adults eclosed under a limited-nutrition condition, the wild-type neuron preserved the branching complexity of the arbor, but scaled down the entire arbor, making a "miniature".

Sensory-neuron subtype-specific transcriptional programs controlling dendrite morphogenesis: genome-wide analysis of Abrupt and Knot/Collier.

The transcription factors Abrupt (Ab) and Knot (Kn) act as selectors of distinct dendritic arbor morphologies in two classes of Drosophila sensory neurons, termed class I and class IV, respectively. We performed binding-site mapping and transcriptional profiling of these isolated neurons. Their profiles were similarly enriched in cell-type-specific enhancers of genes implicated in neural development.

Snakeskin, a membrane protein associated with smooth septate junctions, is required for intestinal barrier function in Drosophila.

Septate junctions (SJs) are the membrane specializations observed between epithelial cells in invertebrates. SJs play a crucial role in epithelial barrier function by restricting the free diffusion of solutes through the intercellular space. In arthropod species, two morphologically different types of SJs have been described: pleated septate junctions (pSJs) and smooth septate junctions (sSJs), which are specific to ectodermal and endodermal epithelia, respectively.

The seven-pass transmembrane cadherin Flamingo controls dendritic self-avoidance via its binding to a LIM domain protein, Espinas, in Drosophila sensory neurons.

Members of the Flamingo cadherin family are required in a number of different in vivo contexts of neural development. Even so, molecular identities downstream from the family have been poorly understood. Here we show that a LIM domain protein, Espinas (Esn), binds to an intracellular juxtamembrane domain of Flamingo (Fmi), and that this Fmi-Esn interplay elicits repulsion between dendritic branches of Drosophila sensory neurons.

Golden Goal collaborates with Flamingo in conferring synaptic-layer specificity in the visual system.

Neuronal connections are often organized in layers that contain synapses between neurons that have similar functions. In Drosophila, R7 and R8 photoreceptors, which detect different wavelengths, form synapses in distinct medulla layers. The mechanisms underlying the specificity of synaptic-layer selection remain unclear.

Multidendritic sensory neurons in the adult Drosophila abdomen: origins, dendritic morphology, and segment- and age-dependent programmed cell death.

Background: For the establishment of functional neural circuits that support a wide range of animal behaviors, initial circuits formed in early development have to be reorganized. One way to achieve this is local remodeling of the circuitry hardwiring. To genetically investigate the underlying mechanisms of this remodeling, one model system employs a major group of Drosophila multidendritic sensory neurons - the dendritic arborization (da) neurons - which exhibit dramatic dendritic pruning and subsequent growth during metamorphosis.

[Norovirus infection outbreaks in Kyoto City--2006-2007].

We studied 96 mass outbreaks of infectious gastroenteritis due to Norovirus in winter 2006-2007. Of these, 56 occurred in welfare institutions for aging adults 31 in hospitals, and 9 in other facilities such as kinder gardens. Affected staff accounted for 25.

Potential dual molecular interaction of the Drosophila 7-pass transmembrane cadherin Flamingo in dendritic morphogenesis.

Seven-pass transmembrane cadherins (7-TM cadherins) play pleiotropic roles in epithelial planar cell polarity, shaping dendritic arbors and in axonal outgrowth. In contrast to their role in planar polarity, how 7-TM cadherins control dendritic and axonal outgrowth at the molecular level is largely unknown. Therefore, we performed extensive structure-function analysis of the Drosophila 7-TM cadherin Flamingo (Fmi) and investigated the activities of individual mutant forms mostly in dendritogenesis of dendritic arborization (da) neurons.

Flamingo regulates R8 axon-axon and axon-target interactions in the Drosophila visual system.

Photoreceptors (R cells) in the Drosophila retina connect to targets in three distinct layers of the optic lobe of the brain: R1-R6 connect to the lamina, and R7 and R8 connect to distinct layers in the medulla. In each of these layers, R axon termini are arranged in evenly spaced topographic arrays. In a genetic screen for mutants with abnormal R cell connectivity, we recovered mutations in flamingo (fmi).

A mosaic genetic screen for genes necessary for Drosophila mushroom body neuronal morphogenesis.

Neurons undergo extensive morphogenesis during development. To systematically identify genes important for different aspects of neuronal morphogenesis, we performed a genetic screen using the MARCM system in the mushroom body (MB) neurons of the Drosophila brain. Mutations on the right arm of chromosome 2 (which contains approximately 20% of the Drosophila genome) were made homozygous in a small subset of uniquely labeled MB neurons.