Biology subjects

Inagaki, S.

Publications and source records attributed to Inagaki, S..

4 recordsLinked to original sources

bioRxiv2018

Nanopore formation in the cuticle of the insect olfactory sensillum

Insects sense odorants through small (50-200-nm diameter) pores in the cuticle covering the olfactory sensilla. These nanopores serve as a filter, preventing the entry of larger airborne particles and limiting water loss. Here we show that the nanopores in Drosophila originate from a curved ultrathin film formed in the outermost layer of the cuticle, secreted from specialized plasma membrane protrusions. The gore-tex/Osiris23 gene, encoding an endosomal protein, is required for nanopore formation and odor receptivity, and is expressed specifically in developing olfactory shaft cells. The 24-member Osiris gene family is expressed in various cuticle-secreting cells, and is found only in insect genomes. Some Osiris mutants show defective cuticle-associated functions, suggesting that Osiris genes may provide a platform for investigating functional surface nano-fabrication in insects.\n\nOne Sentence SummaryAn insect-specific endosomal protein promotes the formation of nano-scale pore structures of the apical extracellular matrix.

developmental biology↗

bioRxiv2018

Translocation and duplication from CRISPR-Cas9 editing in Arabidopsis thaliana

Cut DNA ends in plants may recombine to form novel molecules. We asked whether CRISPR-Cas9 expression in plants could induce nonhomologous recombination between diverse and heterologous broken DNA ends. We induced two breaks separated by 2.3 or by 8.5 kilobases leading to duplication of the intervening DNA and meiotic transmission of the 2.3kb duplication. Two or more dsDNA breaks in nonhomologous chromosomes led to ligation of breakpoints consistent with chromosome arm translocations. Screening 881 primary transformants we obtained 195 PCR products spanning independent, expected translocation junctions involving ends produced by cutting different loci. Sequencing indicated a true positive rate of 84/91 and demonstrated the occurrence of different junction alleles. A majority of the resulting structures would be deleterious and none were transmitted meiotically. Ligation of interchromosomal, heterologous dsDNA ends suggest that the CRISPR-Cas9 can be used to engineer plant genes and chromosomes in vivo.\n\nSignificance StatementWe explored how genome editing tools such as CRISPR-Cas9 could provide new ways to tailor novel genomic combinations and arrangements. We show that distant cut ends often precisely come together, that cuts in different chromosomes can result in translocations, and that two cuts within a chromosome often result in the duplication of the intervening segment. Formation of multiple structures with precise junctions will enable engineered rearrangements that can be predicted with accuracy.

genetics↗

bioRxiv2017

Shavenbaby and Yorkie mediate Hippo signaling to protect adult stem cells from apoptosis

To compensate for accumulating damages and cell death, adult homeostasis (e.g., body fluids and secretion) requires organ regeneration, operated by long-lived stem cells. How stem cells can survive throughout the animal life yet remains poorly understood. Here we show that the transcription factor Shavenbaby (Svb, OvoL in vertebrates) is expressed in renal/nephric stem cells (RNSCs) of Drosophila and required for their maintenance during adulthood. As recently shown in embryos, Svb function in adult RNSCs further needs a post-translational processing mediated by Polished rice (Pri) smORF peptides and impairing Svb function leads to RNSC apoptosis. We show that Svb interacts both genetically and physically with Yorkie (YAP/TAZ in vertebrates), a nuclear effector of the Hippo pathway, to activate the expression of the inhibitor of apoptosis DIAP1. These data therefore identify Svb as a novel nuclear effector in the Hippo pathway, critical for the survival of adult somatic stem cells.

developmental biology↗

bioRxiv2017

In vivo brain activity imaging of interactively locomoting mice

Electrophysiological field potential dynamics have been widely used to investigate brain functions and related psychiatric disorders. Conversely, however, various technical limitations of conventional recording methods have limited its applicability to freely moving subjects, especially when they are in a group and socially interacting with each other. Here, we propose a new method to overcome these technical limitations by introducing a bioluminescent voltage indicator called LOTUS-V. Using our simple and fiber-free recording method, named \"SNIPA,\" we succeeded in capturing brain activity in freely-locomotive mice, without the need for complicated instruments. This novel method further allowed us to simultaneously record from multiple independently-locomotive animals that were interacting with one another. Further, we successfully demonstrated that the primary visual cortex was activated during the interaction. This methodology will further facilitate a wide range of studies in neurobiology and psychiatry.

neuroscience↗