Graded activity of transcription factor Runx3 specifies the laminar termination pattern of sensory axons in the developing spinal cord.
Different functional classes of dorsal root ganglion sensory neurons project their axons to distinct target zones within the developing spinal cord. To explore the mechanisms that link sensory neuron subtype identity and axonal projection pattern, we analyzed the roles of Runx and ETS transcription factors in the laminar targeting of sensory afferents. Gain- and loss-of-function studies in chick embryos reveal that the status of Runx3 expression is a major determinant of the dorso-ventral position of termination of proprioceptive and cutaneous sensory axons. In addition, the level of expression and/or activity of Runx3 in individual proprioceptive sensory neurons appears to specify whether their axons terminate in intermediate or ventral regions. Our findings suggest that the selectivity of Runx3 expression, and its level of activity, control sensory afferent targeting in the developing spinal cord.
Chen
Albert I
AI
Howard Hughes Medical Institute, Department of Biochemistry & Molecular Biophysics, Center for Neurobiology & Behavior, Columbia University, 701 West 168th Street, New York, New York 10032, USA.
de Nooij
Joriene C
JC
Jessell
Thomas M
TM
D000818:Animals; D001369:Axons / Q000187:drug effects / Q000502:physiology*; D002452:Cell Count / Q000379:methods; D002642:Chick Embryo; D050676:Core Binding Factor Alpha 2 Subunit / Q000378:metabolism; D050677:Core Binding Factor Alpha 3 Subunit / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D018274:Electroporation / Q000379:methods; D005455:Fluorescent Antibody Technique / Q000379:methods; D007839:Functional Laterality; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000502:physiology; D016259:Genes, myc / Q000502:physiology; D049452:Green Fluorescent Proteins / Q000378:metabolism; D018398:Homeodomain Proteins / Q000378:metabolism; D008954:Models, Biological; D008967:Molecular Biology / Q000379:methods; D009412:Nerve Fibers / Q000378:metabolism; D009416:Nerve Regeneration / Q000502:physiology; D009475:Neurons, Afferent / Q000145:classification / Q000166:cytology* / Q000187:drug effects; D012330:RNA, Double-Stranded / Q000494:pharmacology; D020917:Receptor, trkA / Q000378:metabolism; D013116:Spinal Cord / Q000166:cytology* / Q000196:embryology
D050676:Core Binding Factor Alpha 2 Subunit; D050677:Core Binding Factor Alpha 3 Subunit; D018398:Homeodomain Proteins; D012330:RNA, Double-Stranded; D049452:Green Fluorescent Proteins; D020917:Receptor, trkA