title: Distinct populations of GABAergic neurons in mouse rhombomere 1 express but do not require the homeodomain transcription factor PITX2.
abstract: Hindbrain rhombomere 1 (r1) is located caudal to the isthmus, a critical organizer region, and rostral to rhombomere 2 in the developing mouse brain. Dorsal r1 gives rise to the cerebellum, locus coeruleus, and several brainstem nuclei, whereas cells from ventral r1 contribute to the trochlear and trigeminal nuclei as well as serotonergic and GABAergic neurons of the dorsal raphe. Recent studies have identified several molecular events controlling dorsal r1 development. In contrast, very little is known about ventral r1 gene expression and the genetic mechanisms regulating its formation. Neurons with distinct neurotransmitter phenotypes have been identified in ventral r1 including GABAergic, serotonergic, and cholinergic neurons. Here we show that PITX2 marks a distinct population of GABAergic neurons in mouse embryonic ventral r1. This population appears to retain its GABAergic identity even in the absence of PITX2. We provide a comprehensive map of markers that places these PITX2-positive GABAergic neurons in a region of r1 that intersects and is potentially in communication with the dorsal raphe.
authors.affiliation: Program in Cell and Molecular Biology, 2966 Taubman Medical Library, University of Michigan, Ann Arbor, MI 48109-0619, USA. Electronic address: mrwaite@umich.edu.
authors.forename: Mindy R
authors.initials: MR
authors.lastname: Waite
authors.affiliation: Department of Neurology, 3520A MSRB I, University of Michigan, Ann Arbor, MI, 48019-5652, USA. Electronic address: kskaggs@umich.edu.
authors.forename: Kaia
authors.initials: K
authors.lastname: Skaggs
authors.affiliation: Department of Pediatrics, 3520A MSRB I, University of Michigan, Ann Arbor, MI, 48019-5652, USA. Electronic address: pkaviany@umich.edu.
authors.forename: Parisa
authors.initials: P
authors.lastname: Kaviany
authors.affiliation: Department of Pediatrics, 3520A MSRB I, University of Michigan, Ann Arbor, MI, 48019-5652, USA. Electronic address: camelot@umich.edu.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Skidmore
authors.affiliation: Institut Jacques Monod, Université Paris Diderot, CNRS UMR 7592, Sorbonne Paris Cité, Paris, France. Electronic address: causeret.frederic@ijm.univ-paris-diderot.fr.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Causeret
authors.affiliation: Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Cardiomyocyte Renewal Lab Texas Heart Institute, Houston Texas, 77030, USA. Electronic address: jmartin@ibt.tamhsc.edu.
authors.forename: James F
authors.initials: JF
authors.lastname: Martin
authors.affiliation: Program in Cell and Molecular Biology, 2966 Taubman Medical Library, University of Michigan, Ann Arbor, MI 48109-0619, USA; Department of Pediatrics, 3520A MSRB I, University of Michigan, Ann Arbor, MI, 48019-5652, USA; Department of Human Genetics, 3520A MSRB I, University of Michigan, Ann Arbor, MI, 48019-5652, USA. Electronic address: donnamm@umich.edu.
authors.forename: Donna M
authors.initials: DM
authors.lastname: Martin
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D002531:Cerebellum / Q000196:embryology / Q000378:metabolism; D059330:GABAergic Neurons / Q000145:classification / Q000166:cytology / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D012249:Rhombencephalon / Q000166:cytology* / Q000196:embryology / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D000097577:Homeobox Protein PITX2
chemical_list: D018398:Homeodomain Proteins; D014157:Transcription Factors; D000097577:Homeobox Protein PITX2