title: Molecular markers for X-ray-insensitive differentiated cells in the Inner and outer regions of the mesenchymal space in planarian Dugesia japonica.
abstract: Planarian's strong regenerative ability is dependent on stem cells (called neoblasts) that are X-ray-sensitive and proliferative stem cells. In addition to neoblasts, another type of X-ray-sensitive cells was newly identified by recent research. Thus, planarian's X-ray-sensitive cells can be divided into at least two populations, Type 1 and Type 2, the latter corresponding to planarian's classically defined "neoblasts". Here, we show that Type 1 cells were distributed in the outer region (OR) immediately underneath the muscle layer at all axial levels from head to tail, while the Type 2 cells were distributed in a more internal region (IR) of the mesenchymal space at the axial levels from neck to tail. To elucidate the biological significance of these two regions, we searched for genes expressed in differentiated cells that were locate close to these X-ray-sensitive cell populations in the mesenchymal space, and identified six genes mainly expressed in the OR or IR, named OR1, OR2, OR3, IR1, IR2 and IR3. The predicted amino acid sequences of these genes suggested that differentiated cells expressing OR1, OR3, IR1, or IR2 provide Type 1 and Type 2 cells with specific extracellular matrix (ECM) environments.
authors.affiliation: Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan.
authors.forename: Machiko
authors.initials: M
authors.lastname: Teramoto
authors.affiliation: Center for Developmental Biology, RIKEN, Kobe, Hyogo, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Kudome-Takamatsu
authors.affiliation: Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan.|Global COE Program: Evolution and Biodiversity, Graduate School of Science, Kyoto University, Kyoto, Japan.|Center for Life Science Technologies, RIKEN, Kobe, Hyogo, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Nishimura
authors.affiliation: Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan.|Immolife-biotech Co. Ltd., Nanking, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: An
authors.affiliation: Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kashima
authors.affiliation: Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan.|Department of Integrated Science and Technology, National Institute of Technology, Tsuyama College 624-1, Tsuyama-City, Okayama, Japan.
authors.forename: Norito
authors.initials: N
authors.lastname: Shibata
authors.affiliation: Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan. agata@mdb.biophys.kyoto-u.ac.jp.|Center for Developmental Biology, RIKEN, Kobe, Hyogo, Japan. agata@mdb.biophys.kyoto-u.ac.jp.|Global COE Program: Evolution and Biodiversity, Graduate School of Science, Kyoto University, Kyoto, Japan. agata@mdb.biophys.kyoto-u.ac.jp.
authors.forename: Kiyokazu
authors.initials: K
authors.lastname: Agata
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D015415:Biomarkers / Q000032:analysis* / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics / Q000528:radiation effects; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000528:radiation effects; D015801:Helminth Proteins / Q000235:genetics / Q000378:metabolism; D008648:Mesoderm / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects; D010932:Planarians / Q000196:embryology* / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D034741:RNA, Small Interfering / Q000378:metabolism / Q000494:pharmacology; D011836:Radiation Tolerance; D014965:X-Rays
chemical_list: D015415:Biomarkers; D015801:Helminth Proteins; D034741:RNA, Small Interfering
keywords: extracellular matrix; mesenchymal space; planarian; stem cell regulation