Planarian homologs of netrin and netrin receptor are required for proper regeneration of the central nervous system and the maintenance of nervous system architecture.
Conserved axon guidance mechanisms are essential for proper wiring of the nervous system during embryogenesis; however, the functions of these cues in adults and during regeneration remain poorly understood. Because freshwater planarians can regenerate a functional central nervous system (CNS) from almost any portion of their body, they are useful models in which to study the roles of guidance cues during neural regeneration. Here, we characterize two netrin homologs and one netrin receptor family member from Schmidtea mediterranea. RNAi analyses indicate that Smed-netR (netrin receptor) and Smed-netrin2 are required for proper CNS regeneration and that Smed-netR may mediate the response to Smed-netrin2. Remarkably, Smed-netR and Smed-netrin2 are also required in intact planarians to maintain the proper patterning of the CNS. These results suggest a crucial role for guidance cues, not only in CNS regeneration but also in maintenance of neural architecture.
Cebrià
Francesc
F
Department of Cell and Developmental Biology and Neuroscience Program, University of Illinois at Urbana-Champaign, B107 Chemical and Life Sciences Laboratory, 601 South Goodwin Avenue, Urbana, IL 61801, USA.
Newmark
Phillip A
PA
D000818:Animals; D019521:Body Patterning; D002465:Cell Movement / Q000502:physiology*; D002490:Central Nervous System / Q000033:anatomy & histology / Q000502:physiology; D017403:In Situ Hybridization; D008027:Light; D009414:Nerve Growth Factors / Q000235:genetics / Q000378:metabolism*; D000075386:Netrin Receptors; D000075388:Netrin-1; D000075385:Netrins; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D017956:Photoreceptor Cells, Invertebrate / Q000166:cytology / Q000378:metabolism; D010932:Planarians / Q000033:anatomy & histology / Q000502:physiology; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D012038:Regeneration; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*
D009414:Nerve Growth Factors; D000075386:Netrin Receptors; D000075385:Netrins; D020033:Protein Isoforms; D011956:Receptors, Cell Surface; D025521:Tumor Suppressor Proteins; D000075388:Netrin-1; C088894:netrin-2