title: An ensemble of regulatory elements controls Runx3 spatiotemporal expression in subsets of dorsal root ganglia proprioceptive neurons.
abstract: The Runx3 transcription factor is essential for development and diversification of the dorsal root ganglia (DRGs) TrkC sensory neurons. In Runx3-deficient mice, developing TrkC neurons fail to extend central and peripheral afferents, leading to cell death and disruption of the stretch reflex circuit, resulting in severe limb ataxia. Despite its central role, the mechanisms underlying the spatiotemporal expression specificities of Runx3 in TrkC neurons were largely unknown. Here we first defined the genomic transcription unit encompassing regulatory elements (REs) that mediate the tissue-specific expression of Runx3. Using transgenic mice expressing BAC reporters spanning the Runx3 locus, we discovered three REs-dubbed R1, R2, and R3-that cross-talk with promoter-2 (P2) to drive TrkC neuron-specific Runx3 transcription. Deletion of single or multiple elements either in the BAC transgenics or by CRISPR/Cas9-mediated endogenous ablation established the REs' ability to promote and/or repress Runx3 expression in developing sensory neurons. Our analysis reveals that an intricate combinatorial interplay among the three REs governs Runx3 expression in distinct subtypes of TrkC neurons while concomitantly extinguishing its expression in non-TrkC neurons. These findings provide insights into the mechanism regulating cell type-specific expression and subtype diversification of TrkC neurons in developing DRGs.
authors.affiliation: Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Elena
authors.initials: E
authors.lastname: Appel
authors.affiliation: Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Sarit
authors.initials: S
authors.lastname: Weissmann
authors.affiliation: Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, 7610001, Israel.|Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Yehuda
authors.initials: Y
authors.lastname: Salzberg
authors.affiliation: Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Kira
authors.initials: K
authors.lastname: Orlovsky
authors.affiliation: Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Varda
authors.initials: V
authors.lastname: Negreanu
authors.affiliation: Department of Veterinary Resources, The Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Michael
authors.initials: M
authors.lastname: Tsoory
authors.affiliation: Department of Veterinary Resources, The Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Calanit
authors.initials: C
authors.lastname: Raanan
authors.affiliation: Life Science Core Facilities, The Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Ester
authors.initials: E
authors.lastname: Feldmesser
authors.affiliation: Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Yael
authors.initials: Y
authors.lastname: Bernstein
authors.affiliation: Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Orit
authors.initials: O
authors.lastname: Wolstein
authors.affiliation: Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Ditsa
authors.initials: D
authors.lastname: Levanon
authors.affiliation: Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, 7610001, Israel.
authors.forename: Yoram
authors.initials: Y
authors.lastname: Groner
mesh_terms: D000818:Animals; D001259:Ataxia / Q000235:genetics; D001665:Binding Sites; D050677:Core Binding Factor Alpha 3 Subunit / Q000235:genetics* / Q000378:metabolism; D004622:Embryo, Mammalian; D005727:Ganglia, Spinal / Q000166:cytology / Q000196:embryology*; D017353:Gene Deletion; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D008124:Locomotion / Q000235:genetics; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D050436:Regulatory Elements, Transcriptional / Q000235:genetics*; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D050677:Core Binding Factor Alpha 3 Subunit; C493730:Runx3 protein, mouse; D014157:Transcription Factors
keywords: BAC transgenic mice; CRISPR/Cas9 enhancer mutants; DRG TrkC proprioceptive neurons; Runx3 transcription factor; long-range transcription regulatory elements