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Sugimoto, Y.

Publications and source records attributed to Sugimoto, Y..

17 recordsLinked to original sources

Curcumin Enhances Alcoholic Fermentation in Yeast by Promoting Osmotic Stress Adaptation

Spices contain diverse plant secondary metabolites with antimicrobial and antioxidant activities that can influence plant-microbe interactions. Among these metabolites, curcumin and piperine are major bioactive constituents of turmeric and black pepper, respectively. In this study, we demonstrate that curcumin and piperine enhance alcoholic fermentation in the budding yeast Saccharomyces cerevisiae. Curcumin significantly promoted alcoholic fermentation under high-glucose conditions (20-40% glucose), which impose substantial osmotic stress on yeast cells. Under these conditions, curcumin enhanced yeast growth, improved osmotic stress tolerance, and increased resistance to cell wall digestion, suggesting enhanced stress adaptation during fermentation. Furthermore, deletion of HOG1, which encodes the central MAP kinase of the High-Osmolarity Glycerol (HOG) pathway responsible for the osmotic stress response, abolished the fermentation-enhancing effect of curcumin, indicating that Hog1 function is required for this effect. Consistent with this result, transcriptomic and RT-qPCR analyses revealed increased expression of stress adaptation-related genes, including known HOG pathway-responsive genes. In contrast, the expression of genes involved in amino acid catabolism was decreased at 12 h after the initiation of fermentation, while metabolomic analysis revealed increased intracellular levels of amino acids, including glutamate and asparagine, at 24 h. These coordinated transcriptional and metabolic changes are consistent with reduced amino acid catabolism and a shift toward a metabolic state favorable for sustained fermentation. Together, these findings suggest that curcumin enhances alcoholic fermentation under osmotic stress by promoting stress adaptation that supports yeast growth and sustained fermentation.

microbiology↗

BCCWJ-Brain: A Multi-Modal fMRI, MEG, and EEG Dataset of Naturalistic Japanese Reading

We present the BCCWJ-Brain dataset, a multi-modal neuroimaging resource comprising functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG), and electroencephalography (EEG) data recorded from native Japanese speakers reading newspaper articles from the Balanced Corpus of Contemporary Written Japanese (BCCWJ). Neural data were collected from 112 participants (36 fMRI, 35 MEG, and 41 EEG) as they read twenty newspaper articles presented in a Rapid Serial Visual Presentation (RSVP) paradigm. By providing three complementary neuroimaging modalities collected under identical naturalistic reading stimuli, this dataset provides a cognitive benchmark for computational models such as large language models. The dataset is publicly available on the OpenNeuro platform, offering a valuable resource for neuroscience, natural language processing, and related research fields.

neuroscience↗

Quantitative profiling of JMJD6-catalysed lysine hydroxylation reveals residue-dependent oxygen sensitivity

Enzyme-catalysed protein hydroxylation links cellular oxygen availability to protein function, as exemplified by the hydroxylation of hypoxia-inducible factor (HIF). Whereas HIF hydroxylation occurs at three specific residues, lysine hydroxylation catalysed by Jumonji domain-containing protein 6 (JMJD6) occurs at many residues within lysine-rich regions across the proteome. How this widespread modification signals oxygen availability has remained incompletely understood, in part because hydroxylation within lysine-rich regions is difficult to detect. Here we developed an analytical workflow for comprehensive, accurate, and quantitative analysis of lysine hydroxylation in proteomic data from lysine-derivatised samples: optimised database searching improved peptide coverage across lysine-rich regions, while diagnostic immonium ion filtering increased the accuracy of hydroxylysine residue assignment. We further showed that stoichiometry estimated from peptide precursor ion intensities enables reliable comparison across residues and conditions. Applied to bromodomain (BRD) proteins, epigenetic readers containing lysine-rich regions extensively hydroxylated by JMJD6, the workflow revealed marked heterogeneity in the apparent kinetics of hydroxylation among target lysines, with interdependence between neighbouring hydroxylation events. Hypoxia suppressed hydroxylation progressively with increasing severity, preferentially affecting residues with slower apparent kinetics. Together, these findings demonstrate that lysine-rich regions can encode a graded, residue-dependent readout of oxygen availability, providing a framework for investigating how cells calibrate their responses to changes in oxygen levels.

biochemistry↗

Plant-specific tau class glutathione transferases safeguard against lipid oxidation stress through dual detoxification of lipid peroxides and reactive carbonyl species

O_LIOxidation of membrane lipids results in the formation of lipid peroxides (LOOHs) and reactive carbonyl species (RCS), that induce lipid oxidation stress in plants. The plant-specific tau class of glutathione transferases (GSTUs) possess both LOOH peroxidase and RCS-conjugating activities, but their overall contribution to stress tolerance remains unclear. C_LIO_LIWe systematically examined 16 GSTU isozymes of Arabidopsis thaliana and found that all catalysed glutathione-dependent reduction of LOOHs. GSTU17, showing the highest activity, recognized five different isomers of linoleic acid-derived hydroperoxides within comparable catalytic efficiencies. C_LIO_LIT-DNA mutants lacking GSTU3, GSTU17, GSTU18, GSTU19 or GSTU25--isoforms with strong conjugation activities toward acrolein, 4-hydroxynonenal or crotonal--displayed enhanced sensitivity to photooxidative stress, indicating that detoxification of RCS is crucial for oxidative protection. C_LIO_LITranscriptome analyses revealed that exposure to RCS (crotonal, 2-pentenal or 2-hexenal) strongly induced 12 GSTU genes, while other GST classes showed little response. Collectively, these results demonstrate that GSTUs function as a major enzymatic system mitigating lipid oxidation stress in A. thaliana through the combined detoxification of lipid peroxides and their reactive carbonyl products. C_LI

plant biology↗

Developmental changes in the carotid body transcriptome accompanying the maturation of chemosensitivity

The carotid body (CB) chemoreceptors mediate rapid cardiorespiratory reflexes to hypoxia, which mature peri-natally and are vital for fetal hypoxia tolerance and post-natal ventilatory control. This maturation is associated with an increase in the sensitivity of the CB electrophysiological response to hypoxia (chemosensitivity): a process that is incompletely understood but critical to systemic oxygen homeostasis. Hypothesizing that perinatal CB gene expression changes would reveal candidate mechanisms for oxygen chemosensitivity, we studied the CB transcriptome in sheep, where peri-natal CB physiology is well-characterised. CB-mediated cardiovascular reflexes are detectable at fetal day 120, and robust by term (day 145), while hypoxic ventilatory responses are established by post-natal day 15. We performed RNA sequencing on sheep CBs at each of these stages, and adults, along with the superior cervical ganglion (SCG) as an oxygen-insensitive control. This allowed us to define tissue-specific changes in the CB transcriptome correlating with chemosensitivity maturation. Striking, progressive CB enrichment is observed in genes implicated in murine CB chemosensitivity, including potassium channels (KCNK9), mitochondrial complex IV regulators (NDUFA4L2, HIGD1C), and HIF-2 (EPAS1). Genes with this expression pattern are also enriched for regulators of diacylglycerol (DAG), particularly the DAG kinase DGKH: one of the most abundant CB transcripts increasing in parallel with chemosensitivity. Across developmental stages, the CB also exhibits marked down-regulation of metabolic pathways and ATP/GTP consuming processes, potentially providing a state permissive to metabolic signal detection. Together, this builds a detailed picture of the CB transcriptional signature, with core features established in fetal life and conserved across species. Key pointsO_LIThe carotid body (CB) chemoreceptors mediate rapid cardiorespiratory responses to hypoxia, which maintain systemic oxygen homeostasis, but CB dysfunction is also implicated in pathologies including hypertension, heart failure and sudden infant death. C_LIO_LICB-mediated chemoreflexes mature during the peri-natal period, with increasing sensitivity of the oxygen chemosensory response. C_LIO_LIWe performed RNA-seq of CBs from sheep across 3 peri-natal stages and adults, enabling us to identify gene expression changes that correlate with functional state. C_LIO_LIWe describe a CB transcriptomic signature that is conserved across species, established in fetal life, and correlates with maturation. This includes features of a unique metabolic phenotype, and up-regulation of genes encoding the extracellular matrix and diacylglycerol signalling. The top transcription factor correlating with functional maturation is EPAS1/ HIF-2. C_LIO_LIWe anticipate that this data set will be a valuable resource in generating novel hypotheses on mechanisms of oxygen chemosensory function, development and CB-associated pathologies. C_LI

physiology↗

RNA Dynamics Regulate Transcriptional Condensate Vivacity to Drive Gene Coordination

Transcriptional condensates (TCs), enriched with Mediator, orchestrate super-enhancer (SE)-driven gene expression critical for cell identity. However, how their dynamic physical properties shape transcriptional activities remains unclear. Here, we reveal a previously unknown regulatory axis wherein dynamic features of enhancer RNA (eRNA), transcribed but rapidly degraded by the RNA exosome, maintain optimal TC fluidity and stability. Depletion of RNA exosome disrupts TC integrity, altering Mediator and Pol II colocalization, in embryonic stem cells. This TC perturbation attenuates proper transcriptional regulator loading and pause-release regulation, enhances transcriptional noise, and diminishes coordinated eRNA-mRNA expression for SE-associated genes. Multi-omics analyses, live-cell imaging, and computational modeling collectively demonstrate that RNA turnover modulates TC vivacity, facilitating widespread chromatin contacts between SE-containing active A compartments and coordinated transcriptional bursts across SE-associated genes. Our findings establish RNA-dependent condensate dynamics as an essential quality-control mechanism that fine-tunes global transcriptional coordination, maintaining cellular homeostasis and cell identity. HighlightsO_LIRNA exosome is required for the homeostasis of transcriptional condensates (TCs) C_LIO_LIRNA synthesis and decay optimize the fluidity and dynamic properties of TCs C_LIO_LITCs maintain the transcriptional consistency of super-enhancer (SE) genes C_LIO_LITCs support contacts of SE-containing A compartments for coordinated transcription C_LI

molecular biology↗

CYP722A1-driven 16-hydroxylation of carlactonoic acid regulates the floral transition in Arabidopsis

Strigolactones (SLs) are multifunctional plant hormones and rhizosphere signals with diverse structures, broadly categorized as canonical or noncanonical SLs. In Arabidopsis thaliana, SL biosynthesis mutants exhibit increased shoot branching and early flowering, underscoring their roles in developmental regulation. Shoot branching inhibition in Arabidopsis depends on the methylation of carlactonoic acid (CLA), a key intermediate classified as a noncanonical SL, catalyzed by CLA methyltransferase (CLAMT). Canonical SLs primarily function as rhizosphere signals, with their biosynthesis in dicots mediated by CYP722C enzymes. It is hypothesized that Arabidopsis does not produce canonical SL because of the lack of the CYP722C genes in its genome. Instead, Arabidopsis possesses CYP722A1, a member of the previously uncharacterized CYP722A subfamily, distinct from the CYP722C subfamily. This study demonstrates that Arabidopsis cyp722a1 mutants exhibit an earlier floral transition without excessive shoot branching. Biochemical analysis revealed that CYP722A1 catalyzes the hydroxylation of CLA to produce 16-hydroxy-CLA (16-HO-CLA), which is subsequently methylated by CLAMT to form 16-HO-MeCLA. 16-HO-CLA and 16-HO-MeCLA were detected in the wild-type; however, these compounds were absent in max1-4 mutant, which is deficient in CLA synthesis, and in cyp722a1 mutant. These findings indicate the presence of CYP722A1-dependent 16-hydroxylation activity of CLA in Arabidopsis. Moreover, they suggest that hydroxylated CLA specifically regulates floral transition, distinct from branching inhibition. By identifying CYP722A1 as a regulator of floral transition, which is the distinct role of the CYP722A subfamily, this work provides insights into the adaptation of SL structures for specialized biological functions in plant development.

plant biology↗

A meta-analysis of the gut microbiome in inflammatory bowel disease patients identifies disease-associated small molecules

Changes in the gut microbiome have been associated with several human diseases, but the molecular and functional details underlying these associations remain largely unknown. Here, we performed a multi-cohort analysis of small molecule biosynthetic gene clusters (BGCs) in 5,306 metagenomic samples of the gut microbiome from 2,033 Inflammatory Bowel Disease (IBD) patients and 833 matched healthy subjects and identified a group of Clostridia-derived BGCs that are significantly associated with IBD. Using synthetic biology, we discovered and solved the structures of six fatty acid amides as the products of the IBD-enriched BGCs. Using two mouse models of colitis, we show that the discovered small molecules disrupt gut permeability and exacerbate inflammation in chemically and genetically susceptible mice. These findings suggest that microbiome-derived small molecules may play a role in the etiology of IBD and represent a generalizable approach for discovering molecular mediators of microbiome-host interactions in the context of microbiome-associated diseases.

microbiology↗

Insights into stereoselective ring formation in canonical strigolactone: Discovery of a dirigent domain-containing enzyme catalyzing orobanchol synthesis

Strigolactones (SLs) are plant apocarotenoids with diverse functions and structures. The widespread canonical SLs, with distinctive structural variations in their tricyclic lactone known as the ABC-ring, are classified into two types based on the C-ring configurations. The steric C-ring configuration arises during the BC-ring closure downstream of carlactonoic acid (CLA), a biosynthetic intermediate. Most plants stereoselectively produce either type of canonical SLs, e.g., tomato (Solanum lycopersicum) produces orobanchol with -oriented C-ring. The mechanisms governing SL structural diversification are partly understood, with limited insight into the functional implications. Moreover, the precise molecular mechanism for the stereoselective BC-ring closure reaction remains unknown. Herein, we identified an enzyme called the stereoselective BC-ring-forming factor (SRF) from the dirigent protein (DIR) family, especially the DIR-f subfamily, whose biochemical function was previously unidentified, making it a pivotal enzyme in stereoselective canonical SL biosynthesis with the -oriented C-ring. We begin by confirming the exact catalytic function of the tomato cytochrome P450 SlCYP722C, which we previously demonstrated to be involved in the orobanchol biosynthesis [Wakabayashi et al., Sci. Adv. 5, eaax9067 (2019)], to convert CLA to 18-oxocarlactonoic acid. Subsequently, we demonstrate that SRF catalyzes the stereoselective BC-ring closure reaction of 18-oxocarlactonoic acid to form orobanchol. Our approach integrates experimental and computational methods, including SRF structure prediction and molecular dynamics simulations, to propose a catalytic mechanism based on the conrotatory 4{pi}-electrocyclic reaction for stereoselective BC-ring formation in orobanchol. The present study provides insight into the molecular basis of how plants produce SLs with specific stereochemistry in a controlled manner.

plant biology↗

Hif-2α programmes oxygen chemosensitivity in chromaffin cells

The study of transcription factors that determine specialised neuronal functions has provided invaluable insights into the physiology of the nervous system. Peripheral chemoreceptors are neurone-like electro-physiologically excitable cells that link the oxygen content of arterial blood to the neuronal control of breathing. In the adult, this oxygen chemosensitivity is exemplified by the Type I cells of the carotid body and recent work has revealed one isoform of the transcription factor HIF, HIF-2, to have a non-redundant role in the development and function of that organ. Here we show that the activation of HIF-2, including isolated overexpression alone, is sufficient to induce oxygen chemosensitivity in the otherwise unresponsive adult adrenal medulla. This phenotypic change in the adrenal medulla was associated with retention of extra-adrenal paraganglioma-like tissues that resemble the foetal organ of Zuckerkandl and also manifest oxygen chemosensitivity. Acquisition of chemosensitivity was associated with changes in the adrenal medullary expression of classes of genes that are ordinarily characteristic of the carotid body, including G-protein regulators and atypical subunits of mitochondrial cytochrome oxidase. Overall, the findings suggest that, at least in certain tissues, HIF-2 acts as a phenotypic driver for cells that display oxygen chemosensitivity, providing a route to mechanistic understanding.

developmental biology↗

Embodied Latch Mechanism of the Mandible to Power at an Ultrahigh Speed in the Trap-jaw Ants Odontomachus kuroiwae

Rapid movements of limbs and appendages, faster than those produced by simple muscle contraction alone, are generated through mechanical networks consisting of springs and latches. The latch plays a central role in these spring-loaded mechanisms, but the structural details of the latch are not always known. The mandibles of the trapjaw ant Odontomachus kuroiwae closes the mandible extremely quickly to capture prey or to perform mandible-powered defensive jumps to avoid potential threats. The jump is mediated by a mechanical spring and latch system embodied in the mandible. An ant can strike the tip of the mandible onto the surface of an obstacle (prey, predator, or ground) in order to bounce its body away from potential threats. The angular velocity of the closing mandible was 2.3x104 rad/s. Latching of the joint is a key mechanism to aid the storage of energy required to power the ballistic movements of the mandibles. We have identified the fine structure of two latch systems on the mandible forming a balljoint using an X-ray micro-computational tomography system (X-ray micro-CT) and X-ray live imaging with a synchrotron. Here we describe the surface of the inner section of the socket and a projection on the lip of the ball. The X-ray live imaging and movements of the 3D model show that the ball with a detent ridge slipped into a socket and over the socket ridge before snapping back at the groove edge. Our results give insight into the complex spring-latch systems that underpin ultra-fast movements in biological systems.

animal behavior and cognition↗

A case of mycobacteriosis associated with Mycobacterium pseudoshottsii in aquarium-reared fish in Japan

In 2019, several aquarium-reared fish died at a sea life park in Japan. Necropsy revealed micronodules on the spleen in the dotted gizzard shad (Konosirus punctatus). Seven of 16 fish exhibited microscopic multifocal granulomas associated with acid-fast bacilli in the spleen, kidney, liver, alimentary tract, mesentery, gills, and/or heart. Bacterial cultures yielded isolates from the dotted gizzard shad and a Japanese sardine (Sardinops melanostictus). Microbiological examination, multilocus sequence typing analysis, and variable number of tandem repeats analysis with a newly proposed 6-loci set revealed the isolates as Mycobacterium pseudoshottsii. To our knowledge, this is the first isolation of M. pseudoshottsii from aquarium-reared fish.

microbiology↗

Isoform resolved measurements of absolute translational efficiency define interplay of HIF and mTOR dysregulation in kidney cancer

Hypoxia inducible factor (HIF) and mammalian target of rapamycin (mTOR) pathways orchestrate responses to oxygen and nutrient availability. These pathways are frequently dysregulated in cancer, but their interplay is poorly understood, in part because of difficulties in simultaneous measurement of global and mRNA-specific translation. Here we describe a workflow for measurement of absolute translational efficiency of mRNAs resolved by their transcription start sites (TSSs). Its application to kidney cancer cells revealed a remarkable extent of translational reprogramming by mTOR, strongly affecting many metabolic enzymes and pathways. By contrast, global effects of HIF on translation were limited, and we did not observe reported translational activation by HIF2A. In contrast, HIF-dependent alterations in TSS usage were associated with robust changes in translational efficiency in a subset of genes. Analyses of the interplay of HIF and mTOR revealed that specific classes of HIF1A and HIF2A transcriptional target gene manifest markedly different sensitivity to mTOR, in a manner that supports combined use of HIF2A and mTOR inhibitors in treatment of kidney cancer.

molecular biology↗

Localization of planteose hydrolysis during seed germination of Orobanche minor

Root parasitic weeds of the Orobanchaceae, such as witchweeds (Striga spp.) and broomrapes (Orobanche and Phelipanche spp.), cause serious losses in agriculture worldwide. No practical method to control these parasitic weeds has been developed to date. Understanding the characteristic physiological processes in the life cycles of root parasitic weeds is particularly important to identify specific targets for growth modulators. In our previous study, planteose metabolism was revealed to be activated soon after the perception of strigolactones in germinating seeds of O. minor. Nojirimycin inhibited planteose metabolism and impeded seed germination of O. minor, indicating that planteose metabolism is a possible target for root parasitic weed control. In the present study, we investigated the distribution of planteose in dry seeds of O. minor by matrix-assisted laser desorption/ionization-mass spectrometry imaging. Planteose was detected in tissues surrounding--but not within--the embryo, supporting its suggested role as a storage carbohydrate. Biochemical assays and molecular characterization of an -galactosidase family member, OmAGAL2, indicated the enzyme is involved in planteose hydrolysis in the apoplast around the embryo after the perception of strigolactones to provide the embryo with essential hexoses for germination. These results indicated that OmAGAL2 is a potential molecular target for root parasitic weed control. HighlightPlanteose accumulated in tissues surrounding the embryo in Orobanche minor dry seeds and was indicated to be hydrolyzed in the apoplast around the embryo by -galactosidase during germination.

plant biology↗

Pseudomonas aeruginosa detachment from surfaces via a self-made small molecule

Pseudomonas aeruginosa is a significant threat in both healthcare and industrial biofouling. Surface attachment of P. aeruginosa is particularly problematic as surface association induces virulence and biofilm formation, which hamper later antibiotic treatments. Previous efforts have searched for biofilm dispersal agents, but there are no known factors that specifically disperse surface-attached P. aeruginosa. In this study we develop a quantitative surface-dispersal assay and use it to show that P. aeruginosa itself produces factors that can stimulate its dispersal. Through bioactivity-guided fractionation, Mass Spectrometry, and Nuclear Magnetic Resonance, we elucidated the structure of one such factor, 2-methyl-4-hydroxyquinoline (MHQ). MHQ is an alkyl-quinolone with a previously unknown activity and is synthesized by the PqsABC enzymes. Pure MHQ is sufficient to disperse P. aeruginosa, but the dispersal activity of natural P. aeruginosa conditioned media requires additional factors. Whereas other alkyl quinolones have been shown to act as antibiotics or membrane depolarizers, MHQ lacks these activities and known antibiotics do not induce dispersal. In contrast, we show that MHQ inhibits the activity of Type IV Pili (TFP) and that TFP targeting can explain its dispersal activity. Our work thus identifies surface dispersal as a new activity of P. aeruginosa-produced small molecules, characterizes MHQ as a promising dispersal agent, and establishes TFP inhibition as a viable mechanism for P. aeruginosa dispersal. Significance StatementWe discovered that the clinically relevant human bacterial pathogen P. aeruginosa, typically associated with surface-based infections, is dispersed by a small molecule that the bacteria themselves produce. We elucidate the chemical structure of this molecule and find that mechanistically it functions to inhibit the activity of the P. aeruginosa extra cellular surface motility appendage, the type IV pilus.

microbiology↗

PP2AB55δ Responsible for the High Initial Rates of Alcoholic Fermentation in Sake Yeast Strains of Saccharomyces cerevisiae

Sake yeast strain Kyokai no. 7 (K7) and its Saccharomyces cerevisiae relatives carry a homozygous loss-of-function mutation in the RIM15 gene, which encodes a Greatwall-family protein kinase. Disruption of RIM15 in non-sake yeast strains leads to improved alcoholic fermentation, indicating that the defect in Rim15p is associated with the enhanced fermentation performance of sake yeast cells. In order to understand how Rim15p mediates fermentation control, we here focused on target-of-rapamycin protein kinase complex 1 (TORC1) and protein phosphatase 2A with the B55{Delta} regulatory subunit (PP2AB55{delta}), complexes that are known to act upstream and downstream of Rim15p, respectively. Several lines of evidence, including our previous transcriptomic analysis data, suggested enhanced TORC1 signaling in sake yeast cells during sake fermentation. Fermentation tests of the TORC1-related mutants using a laboratory strain revealed that TORC1 signaling positively regulates the initial fermentation rate in a Rim15p-dependent manner. Deletion of the CDC55 gene encoding B55{delta} abolished the high fermentation performance of Rim15p-deficient laboratory yeast and sake yeast cells, indicating that PP2AB55{delta} mediates the fermentation control by TORC1 and Rim15p. The TORC1-Greatwall-PP2AB55{delta} pathway similarly affected the fermentation rate in the fission yeast Schizosaccharomyces pombe, strongly suggested that the evolutionarily conserved pathway governs alcoholic fermentation in yeasts. It is likely that elevated PP2AB55{delta} activity accounts for the high fermentation performance of sake yeast cells. Heterozygous loss-of-function mutations in CDC55 found in K7-related sake strains may indicate that the Rim15p-deficient phenotypes are disadvantageous to cell survival.\n\nIMPORTANCEThe biochemical processes and enzymes responsible for glycolysis and alcoholic fermentation by the yeast S. cerevisiae have long been the subject of scientific research. Nevertheless, the factors determining fermentation performance in vivo are not fully understood. As a result, the industrial breeding of yeast strains has required empirical characterization of fermentation by screening numerous mutants through laborious fermentation tests. To establish a rational and efficient breeding strategy, key regulators of alcoholic fermentation need to be identified. In the present study, we focused on how sake yeast strains of S. cerevisiae have acquired high alcoholic fermentation performance. Our findings provide a rational molecular basis to design yeast strains with optimal fermentation performance for production of alcoholic beverages and bioethanol. In addition, as the evolutionarily conserved TORC1-Greatwall-PP2AB55{delta} pathway plays a major role in the glycolytic control, our work may contribute to research on carbohydrate metabolism in higher eukaryotes.

microbiology↗

Excretion initiates walking in the cricket Gryllus bimaculatus

Feces contain information about the donor and potentially attracts both conspecifics and predators and parasites. The excretory system must be coordinated with other behaviors in insects. We found that crickets start walking forward following excretion of feces. Most intact crickets walked around the experimental arena, stopped at a particular site and raised up their body with a slight backward drift to excrete feces. After the feces dropped on the floor, the animal started walking with a random gait pattern away from the feces, and then changed the gait pattern to a tripod gait. Headless cricket also showed walking following excretion. In more than half of excretion events, headless crickets walked backward before excretion. The posture adopted during excretion was similar to that of intact crickets, and post-excretory forward walking was also observed. The occurrence rate of post-excretory walking was more than that of intact crickets. The gait pattern during forward walking was random and never transitioned to a tripod gait in the headless crickets. In animals whose abdominal nerve cords were cut, in any position, pre- or post-excretion walking was not shown in both intact and headless crickets, although they excreted feces. These results indicate that ascending signals from the terminal abdominal ganglion initiate leg movement through the neuronal circuits within thoracic ganglia, and that descending signals from the brain must regulate leg the motor circuit to express the appropriate walking gait.

animal behavior and cognition↗