Biology subjects

Takeshita, N.

Publications and source records attributed to Takeshita, N..

5 recordsLinked to original sources

bioRxiv2025

The increase in cell volume and nuclear number of the koji-fungus Aspergillus oryzae contributes to its high enzyme productivity

While the ratio of nuclei to cell volume is well regulated, it remains largely unexplored in multinucleate organisms. The koji-fungus Aspergillus oryzae, traditionally used in Japanese brewing and fermentation for over a thousand years, is now widely utilized in modern biotechnology as a host for enzyme production. We discovered that, over time in culture, hyphae become thicker, resulting in a tenfold increase in cell volume, and the number of nuclei in hyphal cells also increases tenfold, exceeding 200. The increase in cell volume and nuclear number is unique among the investigated Aspergillus species and correlates with its high enzyme production capabilities. Since nuclear number and cell volume are correlated, both must increase simultaneously for either to expand. Our analyses identified genetic factors and nutritional environmental signals involved in each of these increases. Increases in nuclear number and cell volume were also observed in other fungi bred for industrial use. This study not only deepens our understanding of the evolutionary processes that promote high enzyme productivity through fungal breeding, but also provides insights into the molecular mechanisms regulating cell volume and nuclear number in multinucleate organisms.

microbiology↗

bioRxiv2023

Acto3D: user- and budget-friendly software for multichannel high-resolution three-dimensional imaging

Advances in fluorescence microscopy and tissue-clearing technology have revolutionized three-dimensional (3D) imaging of fluorescently labeled tissues, organs, and embryos. However, the complexity and high cost of existing software and computer solutions for such imaging limit its widespread adoption by researchers with limited resources. We here introduce Acto3D as a user- and budget-friendly, open-source computer software application designed to streamline the generation and observation of high-resolution 3D images of targets labeled with multiple fluorescent probes. Acto3D features an intuitive interface that simplifies the importation, visualization, and analysis of data sets, has an associated tool for annotation of vascular lumens, and incorporates multiple fluorescence channels for comprehensive imaging. Underpinned by an integrated graphics processing unit, Acto3D allows accurate image reconstruction and efficient data processing without the need for expensive high-performance computers. We validated the software by imaging mouse embryonic structures. Acto3D thus constitutes a cost-effective and efficient platform to support biological research.

developmental biology↗

bioRxiv2023

Ciliary protein CEP290 regulates focal adhesion via microtubule system in non-ciliated cells

Almost all differentiated mammalian cells have primary cilia on their surface. Ciliary dysfunction causes ciliopathy in humans. Centrosomal protein 290 (CEP290) is a ciliary protein that causes ciliopathies, localizes at the cilial base in ciliated cells, whereas it localizes to the centrosome in non-ciliated proliferating cells. The cilia-dependent function of CEP290 has been extensively studied; however, the cilia-independent function, which is likely responsible for the wider phenotypic spectra of CEP290-related ciliopathies, remains largely unknown. Here, we examined cilia-independent functions of CEP290 in non-ciliated cells. Our study showed that Cep290 function loss suppresses microtubule elongation due to microtubule organizing center malfunction. Surprisingly, CEP290 forms a complex with the adenomatous polyposis coli (APC) protein encoded by the adenomatous polyposis coli gene. The APC-CEP290 complex exists in the centrosome and on microtubule fibers. Notably, the reduced focal adhesion formation is likely responsible for the Cep290 mutant phenotypes, including impaired directed cell migration, shrunken cell shape, and reduced adhesive capacity to the extracellular matrix. The APC-CEP290 complex is consistently important for transporting a focal adhesion molecule, paxillin, to focal adhesions in non-ciliated cells. Thus, our findings provide a novel platform to better understand the ciliopathies.

cell biology↗

bioRxiv2020

Trade-off between plasticity and velocity in mycelial growth

Tip-growing fungal cells maintain the cell polarity at the apical regions and elongate by de novo synthesis of cell wall. Cell polarity and growth rate affect the mycelial morphogenesis, however, it remains unclear how they act cooperatively to determine cell shape. Here we investigated their relationship by analyzing hyphal tip growth of filamentous fungi growing inside extremely narrow 1 m-width channels of microfluidic devices. Since the channels are much narrower than the diameter of hyphae, the hyphae must change its morphology when they grow through the channels. Live imaging analysis revealed that hyphae of some species continued growing through the channels, whereas hyphae of other species often ceased growing when passing through the channels or lost the cell polarity after emerging from the channels. Fluorescence live imaging analysis of the Spitzenkorper, a collection of secretory vesicles and polarity-related proteins at hyphal tips, in Neurospora crassa hyphae indicates that hyphal tip growth requires a very delicate balance of ordered exocytosis to maintain polarity in spatially confined environments. We analyzed the mycelial growth of seven fungal species from different lineages, which also include phytopathogenic fungi. This comparative cell biology showed that the growth defects in the channels were not correlated with their taxonomic classification nor with the width of hyphae, but, correlated with the hyphal elongation rate. This is the first report indicating a trade-off between plasticity and velocity in mycelial growth, and serves to understand fungal invasive growth into substrates or plant/animal cells, with direct impact on fungal biotechnology, ecology and pathogenicity.

microbiology↗

bioRxiv2019

Comparative genomics reveals the origin of fungal hyphae and multicellularity

Hyphae represent a hallmark structure of multicellular fungi with immense importance in their life cycle, including foraging for nutrients, reproduction, or virulence. Hypha morphogenesis has been the subject to intense interest, yet, the origins and genetic underpinning of the evolution of hyphae are hardly known. Using comparative genomics, we here show that the emergence of hyphae correlates with multiple types of genetic changes, including alterations of gene structure, gene family diversification as well as co-option and exaptation of ancient eukaryotic genes (e.g. phagocytosis-related genes). Half of the gene families involved in hypha morphogenesis have homologs in unicellular fungi and non-fungal eukaryotes and show little or no duplications coincident with the origin of multicellular hyphae. Considerable gene family diversification was observed only in transcriptional regulators and genes related to cell wall synthesis and modification. Despite losing 35-46% of their genes, yeasts retained significantly more multicellularity-related genes than expected by chance. We identified 414 gene families that evolved in a correlated fashion with hyphal multicellularity and may have contributed to its evolution. Contrary to most multicellular lineages, the origin of hyphae did not correlate with the expansion of gene families encoding kinases, receptors or adhesive proteins. Our analyses suggest that fungi took a unique route to multicellularity that involved limited gene family diversification and extensive co-option of ancient eukaryotic genes.

evolutionary biology↗