Biology subjects

Sano, H.

Publications and source records attributed to Sano, H..

9 recordsLinked to original sources

bioRxiv2024

Quantifying Forest Biomass and Genetic Contribution using Light Detection and Ranging

The growing focus on the role of forests in carbon sequestration highlights the importance of accurately and efficiently measuring biophysical traits, such as diameter at breast height (DBH) and tree height. Understanding genetic contributions to trait variation is crucial for enhancing carbon storage through genetic improvement of forest trees. Light detection and ranging (LiDAR) has been used to estimate DBH and tree height; however, few studies have explored the heritability of these traits or assessed the accuracy of biomass increment selections based on these traits. Therefore, this study aimed to leverage LiDAR to measure DBH and tree height, estimate tree heritability, and evaluate the accuracy of timber volume selections based on these traits using 60-year-old larch as the study material. Unmanned aerial vehicle (UAV) and backpack LiDAR were compared against hand-measured values. The accuracy of DBH estimations using backpack LiDAR resulted in a root mean square error (RMSE) of 2.7 cm and a coefficient of determination of 0.67. Conversely, the accuracy achieved with UAV LiDAR was 4.0 cm in RMSE and a 0.24 coefficient of determination. The heritability of DBH was found to be higher for backpack LiDAR than for UAV LiDAR and even exceeded that of hand measurements. Comparisons of the accuracy of timber volume selections based on the measured traits demonstrated comparable performances between the backpack and UAV LiDAR. Overall, these findings underscore the potential of using LiDAR remote sensing to quantitatively measure forest tree biomass and facilitate their genetic improvement of carbon-sequestration ability based on these measurements.

genetics↗

bioRxiv2024

Glutathione supersulphide regulates T-cell receptor signalling

Immunometabolism regulates functions and fates of immune cells including T cells. Supersulphides, which are universal metabolites containing catenated sulphur atoms, have various physiological functions based on their unique redox properties. Here we found that activation of T-cell receptor (TCR) signalling was accompanied by supersulphide decrease, which suggests a regulatory contribution of sulphur metabolism to immune function. Consistently, inhibiting supersulphide synthesis facilitated TCR activation and exacerbated allergen-induced type 2 inflammation in mice. Supplementation with glutathione trisulphide (GSSSG), a major endogenous supersulphide, suppressed TCR signalling in naive CD4+ T cells and their differentiation and effectively alleviated the inflammation. Docking simulation revealed interaction of GSSSG with CD3{varepsilon} chain in the TCR/CD3 complex, which was supported by mass spectrometry detection of persulphidated glutathionylation at a functionally important CXXC motif of CD3{varepsilon} chain. This study identified a new post-translational modification with supersulfides and demonstrated a critical contribution of sulphur metabolism to TCR signalling regulation.

biochemistry↗

bioRxiv2023

Shared GABA transmission pathology in dopamine agonist- and antagonist-induced dyskinesia

Dyskinesia is involuntary movement caused by long-term medication with dopamine-related agents: the dopamine agonist, L-DOPA, to treat Parkinsons disease (L-DOPA-induced dyskinesia [LID]) or dopamine antagonists to treat schizophrenia (tardive dyskinesia [TD]). However, it remains unknown why distinct types of medications for distinct neuropsychiatric disorders induce similar involuntary movements. Here, we searched for a shared structural footprint using magnetic resonance imaging-based macroscopic screening and super-resolution microscopy-based microscopic identification. We identified the enlarged axon terminals of striatal medium spiny neurons in both LID and TD model mice. The striatal overexpression of vesicular gamma-aminobutyric acid transporter (VGAT) was necessary and sufficient for modeling these structural changes; VGAT levels gated the functional and behavioral alterations in dyskinesia models. Our findings indicate that lowered type 2 dopamine receptor signaling with repetitive dopamine fluctuations is a common cause of VGAT overexpression and late-onset dyskinesia formation, and that reducing dopamine fluctuation rescues dyskinesia pathology via VGAT downregulation. HighlightsO_LIEnhancement of GABAergic transmission is a shared mechanism between LID and TD. C_LIO_LIVGAT levels in MSNs govern the structure and function of MSN presynaptic terminals. C_LIO_LIGain and loss of VGAT function in MSNs exacerbates and ameliorates dyskinesia. C_LIO_LILowered D2 signaling with repetitive DA fluctuations causes VGAT overexpression. C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=188 HEIGHT=200 SRC="FIGDIR/small/550763v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@15041b4org.highwire.dtl.DTLVardef@9bf41org.highwire.dtl.DTLVardef@1eb7ee4org.highwire.dtl.DTLVardef@1d7dae8_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2023

Behavioral effects of zonisamide on L-DOPA-induced dyskinesia in Parkinson's disease model mice

Zonisamide (ZNS; 1,2-benzisoxazole-3-methanesulfonamide) was initially developed and is commonly used as an anticonvulsant drug. However, it has also shown beneficial effects on Parkinsons disease (PD), a progressive neurodegenerative disorder caused by the loss of dopaminergic neurons in the midbrain. Recent clinical studies have suggested that ZNS can also have beneficial effects on L-DOPA-induced dyskinesia (LID), which is a major side effects of long-term L-DOPA treatments for PD. In the present study, we examined the behavioral effects of ZNS on LID in PD model mice. Acute ZNS treatment did not have any observable behavioral effects on LID. Contrastingly, chronic ZNS treatment with L-DOPA delayed the peak of LID and reduced the severity of LID before the peak, but increased the duration of LID in a dose-dependent manner of ZNS, compared to PD model mice treated with L-DOPA alone. Thus, ZNS appears to have both beneficial and adverse effects on LID.

neuroscience↗

bioRxiv2022

Spatial attention in perceptual decision making as revealed by response-locked classification image analysis

In many situations, humans serially sample information from many locations in an image to make an appropriate decision about a visual target. Spatial attention plays a crucial role in this serial vision process. To investigate the effect of spatial attention in such dynamic decision making, we applied a classification image (CI) analysis locked to the observers reaction time (RT). We asked human observers to detect as rapidly as possible a target whose contrast gradually increased on the left or right side of dynamic noise, with the presentation of a spatial cue. The analysis revealed a spatiotemporally biphasic profile of the CI which peaked at [~]350 ms before the observers response. We found that a valid cue presented at the target location shortened the RT and increased the overall amplitude of the CI, especially when the cue appeared 500-1250 ms before the observers response. The results were quantitatively accounted for by a simple perceptual decision mechanism that accumulates the outputs of the spatiotemporal contrast detector, whose gain is increased by sustained attention to the cued location.

neuroscience↗

bioRxiv2021

The polyol pathway is an evolutionarily conserved system for sensing glucose uptake

Cells must adjust the expression levels of metabolic enzymes in response to fluctuating nutrient supply. For glucose, such metabolic remodeling is highly dependent on a master transcription factor ChREBP/MondoA. However, it remains elusive how glucose fluctuations are sensed by ChREBP/MondoA despite the stability of major glycolytic pathways. Here we show that in both flies and mice, ChREBP/MondoA activation in response to glucose ingestion depends on an evolutionarily conserved glucose-metabolizing pathway: the polyol pathway. The polyol pathway converts glucose to fructose via sorbitol. It has been believed that this pathway is almost silent, and its activation in hyperglycemic conditions has deleterious effects on human health. We show that the polyol pathway is required for the glucose-induced nuclear translocation of Mondo, a Drosophila homologue of ChREBP/MondoA, which directs gene expression for organismal growth and metabolism. Likewise, inhibition of the polyol pathway in mice impairs ChREBPs nuclear localization and reduces glucose tolerance. We propose that the polyol pathway is an evolutionarily conserved sensing system for the glucose uptake that allows metabolic remodeling.

physiology↗

bioRxiv2020

Chromosomal-scale De novo Genome Assemblies of Cynomolgus Macaque and Common Marmoset

Cynomolgus macaque (Macaca fascicularis) and common marmoset (Callithrix jacchus) have been widely used in human biomedical research. Their genomes were sequenced and assembled initially using short-read sequences, with the advent of massively parallel sequencing. However, the resulting contig sequences tended to remain fragmentary, and long-standing primate genome assemblies used the human genome as a reference for ordering and orienting the assembled fragments into chromosomes. Here we performed de novo genome assembly of these two species without any human genome-based bias observed in the genome assemblies released earlier. Firstly we assembled PacBio long reads, and the resultant contigs were scaffolded with Hi-C data. The scaffolded sequences obtained were further refined based on assembly results of alternate de novo assemblies and Hi-C contact maps by resolving identified inconsistencies. The final assemblies achieved N50 lengths of 149 Mb and 137 Mb for cynomolgus macaque and common marmoset, respectively, and the numbers of scaffolds longer than 10Mb are equal to their chromosome numbers. The high fidelity of our assembly is ascertained by concordance to the BAC-end read pairs observed for common marmoset, as well as a high resemblance of their karyotypic organization. Our assembly of cynomolgus macaque outperformed all the available assemblies of this species in terms of contiguity. The chromosome-scale genome assemblies produced in this study are valuable resources for non-human primate models and provide an important baseline in human biomedical research.

genomics↗

bioRxiv2020

The polyol pathway is a crucial glucose sensor in Drosophila

A major nutrient source for animals is glucose, which induces transcriptional responses that shift metabolism. Such metabolic adaptation should be appropriately scaled to the ingested glucose levels, and decoupling causes human metabolic diseases. However, the identity of the crucial sensor metabolite(s) that transmit circulating glucose levels to the transcriptional machinery remains elusive. Here we show that the polyol pathway, which converts glucose to fructose via sorbitol, is required for activation of the master metabolic regulator Mondo, the Drosophila homologue of MondoA/ChREBP. We demonstrate that under normal nutritional conditions polyol pathway metabolites promote Mondos nuclear localization and cause global changes in metabolic gene expression. Polyol pathway mutants block nuclear localization of Mondo and Mondo-mediated gene expression despite intact glycolytic and pentose phosphate pathways. Our results uncover the normal physiological function of this pathway and cast a new light on the adverse effects of high fructose diets in human health.

physiology↗

bioRxiv2019

Forelimb movements evoked by optogenetic stimulation of the macaque motor cortex

Optogenetics has become an indispensable tool for investigating brain functions. Although non-human primates are particularly useful models for understanding the functions and dysfunctions of the human brain, application of optogenetics to non-human primates is still limited. In the present study, we generated an effective adeno-associated viral vector serotype DJ to express channelrhodopsin-2 (ChR2) under the control of a strong ubiquitous CAG promoter and injected into the somatotopically identified forelimb region of the primary motor cortex in macaque monkeys. ChR2 was strongly expressed around the injection sites, and optogenetic intracortical microstimulation (oICMS) through a homemade optrode induced prominent cortical activity: Even single-pulse, short duration oICMS evoked long-lasting repetitive firings of cortical neurons. In addition, oICMS elicited distinct forelimb movements and muscle activity, which were comparable to those elicited by conventional electrical ICMS. The present study removed obstacles to optogenetic manipulation of neuronal activity and behaviors in non-human primates.

neuroscience↗