title: A forkhead transcription factor is wound-induced at the planarian midline and required for anterior pole regeneration.
abstract: Planarian regeneration requires positional information to specify the identity of tissues to be replaced as well as pluripotent neoblasts capable of differentiating into new cell types. We found that wounding elicits rapid expression of a gene encoding a Forkhead-family transcription factor, FoxD. Wound-induced FoxD expression is specific to the ventral midline, is regulated by Hedgehog signaling, and is neoblast-independent. FoxD is subsequently expressed within a medial subpopulation of neoblasts at wounds involving head regeneration. Ultimately, FoxD is co-expressed with multiple anterior markers at the anterior pole. Inhibition of FoxD with RNA interference (RNAi) results in the failure to specify neoblasts expressing anterior markers (notum and prep) and in anterior pole formation defects. FoxD(RNAi) animals fail to regenerate a new midline and to properly pattern the anterior blastema, consistent with a role for the anterior pole in organizing pattern of the regenerating head. Our results suggest that wound signaling activates a forkhead transcription factor at the midline and, if the head is absent, FoxD promotes specification of neoblasts at the prior midline for anterior pole regeneration.
authors.affiliation: Howard Hughes Medical Institute, MIT Biology and Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America.
authors.forename: M Lucila
authors.initials: ML
authors.lastname: Scimone
authors.affiliation: Howard Hughes Medical Institute, MIT Biology and Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America.
authors.forename: Sylvain W
authors.initials: SW
authors.lastname: Lapan
authors.affiliation: Howard Hughes Medical Institute, MIT Biology and Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Reddien
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D051858:Forkhead Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins / Q000096:biosynthesis / Q000235:genetics; D015801:Helminth Proteins / Q000096:biosynthesis* / Q000235:genetics; D010932:Planarians / Q000235:genetics / Q000502:physiology; D034622:RNA Interference; D012038:Regeneration / Q000235:genetics*; D015398:Signal Transduction / Q000235:genetics; D013234:Stem Cells; D014947:Wounds and Injuries / Q000235:genetics*
chemical_list: D051858:Forkhead Transcription Factors; D053823:Hedgehog Proteins; D015801:Helminth Proteins