Biology subjects

Kohno, H.

Publications and source records attributed to Kohno, H..

5 recordsLinked to original sources

bioRxiv2025

mKast knockout honey bees show defects in brain functions underlying homing ability

Honey bees visit food sources up to several kilometers away from their hives, which is underpinned by their sophisticated learning and memory, and cognitive abilities. However, the molecular and neural bases for these advanced brain functions remain obscure. Here, we focused on mKast, a gene preferentially expressed in the optic lobes, a visual center, and a specific Kenyon cell subtype in the mushroom bodies, a higher-order center, in the honey bee brain. We successfully produced homozygous mutant honey bee workers by crossing individuals mutated with CRISPR/Cas9 targeting mKast. Through behavioral analyses of mKast mutants using a new conditioning paradigm and a visual response assay, we found that mKast functions in bimodal learning and memory based on olfactory and visual information, and direction-specific motion sensing. We also found that mKast homozygous mutants have defects in survival outside the colony. These findings suggest that mKast modulate brain functions underlying homing ability that is essential for nidificating hymenopteran species.

animal behavior and cognition↗

bioRxiv2025

Analysis of molecular and cellular bases of honey bee mushroom body development

Honey bee mushroom bodies (MBs) comprise three class I Kenyon cell (KC) subtypes (lKC, mKC, and sKC) with distinct somata sizes and locations and gene expression profiles. While these KC subtypes have been suggested to function in different behavioral regulations, the molecular and cellular basis of their development remains obscure. Here, we showed that lKCs, mKCs, and sKCs are produced in that order at different pupal stages by labeling proliferating MB cells with 5-ethynil-2-deoxyuridine at various pupal stages. RNA-sequencing analysis of FACS-sorted pupal MB cells identified genes that were upregulated in proliferating and non-proliferating MB cells, respectively. Furthermore, in situ hybridization of some of these genes labeled the proliferating cells or young KCs in the pupal MBs. Our findings reveal the basic scheme of the molecular and cellular processes of honey bee MB development and suggest that they are at least partially different from those of Drosophila MB development.

developmental biology↗

bioRxiv2023

Analysis of antennal responses to motion stimuli in the honey bee by automated tracking using DeepLabCut

Considering recent developments in gene manipulation methods for honey bees, establishing simple, robust, and indoor assay systems which can analyze behavioral components in detail is important for the rise of honey bee behavioral genetics. We focused on the movements of antennae of the honey bee, which are used for not only multimodal sensory perception but also interactions between individuals. We developed an experimental system for analyzing the antennal responses (ARs) of the honey bee using DeepLabCut, a markerless posture-tracking tool using deep learning. The tracking of antennal movements during the presentation of vertical (downward and upward) motion stimuli using DeepLabCut successfully detected the ARs reported in the previous studies, where bees tilted their antennae in the direction opposite to the motion stimuli. In addition, we successfully detected ARs in response to horizontal (forward and backward) motion stimuli. An investigation of the developmental maturation of honey bee ARs showed that ARs to motion stimuli were not detected in bees immediately after emergence but became detectable through post-emergence development in an experience-independent manner. Furthermore, unsupervised clustering analysis using multidimensional data created by processing tracking data using DeepLabCut classified antennal movements into different clusters, suggesting that data-driven behavioral classification can apply to AR paradigms. These results reveal novel AR to visual stimuli and developmental maturation of ARs and suggest the efficacy of data-driven analysis for behavioral classification in behavioral studies of the honey bee. Summary statementAutomated tracking using DeepLabCut was successfully applied to measure the antennal response to motion stimuli and unsupervised classification of antennal movements in honey bees.

animal behavior and cognition↗

bioRxiv2022

N1-methylpseudouridine-incorporated mRNA enhances exogenous protein expression and suppresses immunogenicity in primary human fibroblast-like synoviocytes

Studies conducted using murine arthritis models have indicated that the use of in vitro-transcribed messenger RNA (IVT mRNA) is an effective therapeutic approach for joint diseases. However, the use of IVT mRNA in human synovial cells has not been widely studied. Recently, the outbreak of the novel coronavirus disease has accelerated the development of innovative mRNA vaccines such as those containing a modified nucleic acid, N1-methylpseudouridine-5'-triphosphate (m1{psi}). IVT mRNA is an attractive tool for biological experiments and drug discovery. To verify the protein expression of IVT mRNA in vitro, primary cultured human fibroblast-like synoviocytes (FLS) were transfected with enhanced green fluorescent protein (EGFP) mRNA with or without m1{psi} incorporation. EGFP was detected using western blotting and fluorescence microscopy. A multiplex assay was performed to comprehensively understand IVT mRNA-induced immunogenicity. FLS transfected EGFP mRNA containing m1{psi} generated higher levels of EGFP than unmodified EGFP mRNA or control RNAs. The multiplex assay of the FLS culture supernatant revealed that concentrations of IL-6, TNF-, and CXCL10 were upregulated by unmodified EGFP mRNA, whereas they were suppressed by EGFP mRNA with m1{psi}. Overall, m1{psi} incorporation enhanced protein expression and decreased cytokine expressions in primary cultured FLS. The findings may contribute to arthritis research.

molecular biology↗

bioRxiv2020

Ccr2 suppression by minocycline in Cx3cr1/Ccr2-visualized inherited retinal degeneration

Retinal inflammation accelerates photoreceptor cell death (PCD) caused by retinal degeneration. Minocycline, a semisynthetic broad-spectrum tetracycline antibiotic, has previously been reported to show PCD rescue effect in retinal degeneration. The purpose of this study was to assess the effect of minocycline on Cx3cr1 and Ccr2 expression in retinal degeneration. Mertk-/-Cx3cr1GFP/+Ccr2RFP/+ mice, which enabled observation of Cx3cr1- and Ccr2-expression pattern in inherited retinal degeneration, were used to test the effect of minocycline. Minocycline was systemically administered to Mertk-/-Cx3cr1GFP/+Ccr2RFP/+ mice. For observing the effect of minocycline on Cx3cr1 and Ccr2 expression, administration was started on 4-week-old mice and continued for 2 weeks. To assess the PCD rescue effect, minocycline was administered to 6-week-old mice for 2 weeks. The expression pattern of Cx3cr1-GFP and Ccr2-RFP were observed on retinal and retinal pigment epithelium (RPE) flat-mounts. The severity of retinal degeneration was assessed on retinal sections. Minocycline administration suppressed Ccr2 expression in Mertk-/-Cx3cr1GFP/+Ccr2RFP/+ mice as observed in retinal and RPE flat-mounts. On the contrary, Cx3cr1 expression was not affected by minocycline administration. Retinal degeneration is ameliorated in minocycline administered Mertk-/-Cx3cr1GFP/+Ccr2RFP/+ mice. In conclusions, Minocycline suppression of Ccr2 expression correlates to amelioration of retinal degeneration.

neuroscience↗