Hedgehog signaling regulates gene expression in planarian glia.
Hedgehog signaling is critical for vertebrate central nervous system (CNS) development, but its role in CNS biology in other organisms is poorly characterized. In the planarianSchmidtea mediterranea, hedgehog (hh) is expressed in medial cephalic ganglia neurons, suggesting a possible role in CNS maintenance or regeneration. We performed RNA sequencing of planarian brain tissue following RNAi ofhhandpatched (ptc), which encodes the Hh receptor. Two misregulated genes,intermediate filament-1 (if-1) andcalamari (cali), were expressed in a previously unidentified non-neural CNS cell type. These cells expressed orthologs of astrocyte-associated genes involved in neurotransmitter uptake and metabolism, and extended processes enveloping regions of high synapse concentration. We propose that these cells are planarian glia. Planarian glia were distributed broadly, but only expressedif-1andcaliin the neuropil nearhh+neurons. Planarian glia and their regulation by Hedgehog signaling present a novel tractable system for dissection of glia biology.
Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.|Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, United States.|Whitehead Institute, Massachusetts Institute of Technology, Cambridge, United States.|Department of Neurobiology, Stanford University, Stanford, United States.
Irving E
IE
Wang
Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.|Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, United States.|Whitehead Institute, Massachusetts Institute of Technology, Cambridge, United States.
Sylvain W
SW
Lapan
Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.|Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, United States.|Whitehead Institute, Massachusetts Institute of Technology, Cambridge, United States.
M Lucila
ML
Scimone
Department of Neurobiology, Stanford University, Stanford, United States.
Thomas R
0000-0001-6277-6849
TR
Clandinin
Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.|Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, United States.|Whitehead Institute, Massachusetts Institute of Technology, Cambridge, United States.
Peter W
0000-0002-5569-333X
PW
Reddien
D000818:Animals; D005786:Gene Expression Regulation; D053823:Hedgehog Proteins / Q000378:metabolism*; D009457:Neuroglia / Q000502:physiology*; D010932:Planarians; D015398:Signal Transduction
D053823:Hedgehog Proteins
Hedgehog signaling; Schmidtea mediterranea; astrocytes; developmental biology; glia; planaria; regeneration; stem cells