title: Regeneration in Macrostomum lignano (Platyhelminthes): cellular dynamics in the neoblast stem cell system.
abstract: Neoblasts are potentially totipotent stem cells and the only proliferating cells in adult Platyhelminthes. We have examined the cellular dynamics of neoblasts during the posterior regeneration of Macrostomum lignano. Double-labeling of neoblasts with bromodeoxyuridine and the anti-phospho histone H3 mitosis marker has revealed a complex cellular response in the first 48 h after amputation; this response is different from that known to occur during regeneration in triclad platyhelminths and in starvation/feeding experiments in M. lignano. Mitotic activity is reduced during the first 8 h of regeneration but, at 48 h after amputation, reaches almost twice the value of control animals. The total number of S-phase cells significantly increases after 1 day of regeneration. A subpopulation of fast-cycling neoblasts surprisingly shows the same dynamics during regeneration as those in control animals. Wound healing and regeneration are accompanied by the formation of a distinct blastema. These results present new insights, at the cellular level, into the early regeneration of rhabditophoran Platyhelminthes.
authors.affiliation: Institute of Zoology, University of Innsbruck, Technikerstrasse 25, Innsbruck 6020, Austria.
authors.forename: Katharina Theresia
authors.initials: KT
authors.lastname: Nimeth
authors.forename: Bernhard
authors.initials: B
authors.lastname: Egger
authors.forename: Reinhard
authors.initials: R
authors.lastname: Rieger
authors.forename: Willi
authors.initials: W
authors.lastname: Salvenmoser
authors.forename: Roland
authors.initials: R
authors.lastname: Peter
authors.forename: Robert
authors.initials: R
authors.lastname: Gschwentner
mesh_terms: D000671:Amputation, Surgical; D000818:Animals; D001973:Bromodeoxyuridine / Q000378:metabolism; D049109:Cell Proliferation; D006657:Histones / Q000276:immunology / Q000378:metabolism; D066298:In Vitro Techniques; D008938:Mitosis / Q000502:physiology; D010986:Platyhelminths / Q000166:cytology / Q000502:physiology*; D012038:Regeneration / Q000502:physiology*; D016196:S Phase; D013997:Time Factors; D039901:Totipotent Stem Cells / Q000166:cytology* / Q000378:metabolism; D014945:Wound Healing / Q000502:physiology
chemical_list: D006657:Histones; D001973:Bromodeoxyuridine