title: A Transgenic Mouse Line Expressing the Red Fluorescent Protein tdTomato in GABAergic Neurons.
abstract: GABAergic inhibitory neurons are a large population of neurons in the central nervous system (CNS) of mammals and crucially contribute to the function of the circuitry of the brain. To identify specific cell types and investigate their functions labelling of cell populations by transgenic expression of fluorescent proteins is a powerful approach. While a number of mouse lines expressing the green fluorescent protein (GFP) in different subpopulations of GABAergic cells are available, GFP expressing mouse lines are not suitable for either crossbreeding to other mouse lines expressing GFP in other cell types or for Ca2+-imaging using the superior green Ca2+-indicator dyes. Therefore, we have generated a novel transgenic mouse line expressing the red fluorescent protein tdTomato in GABAergic neurons using a bacterial artificial chromosome based strategy and inserting the tdTomato open reading frame at the start codon within exon 1 of the GAD2 gene encoding glutamic acid decarboxylase 65 (GAD65). TdTomato expression was observed in all expected brain regions; however, the fluorescence intensity was highest in the olfactory bulb and the striatum. Robust expression was also observed in cortical and hippocampal neurons, Purkinje cells in the cerebellum, amacrine cells in the retina as well as in cells migrating along the rostral migratory stream. In cortex, hippocampus, olfactory bulb and brainstem, 80% to 90% of neurons expressing endogenous GAD65 also expressed the fluorescent protein. Moreover, almost all tdTomato-expressing cells coexpressed GAD65, indicating that indeed only GABAergic neurons are labelled by tdTomato expression. This mouse line with its unique spectral properties for labelling GABAergic neurons will therefore be a valuable new tool for research addressing this fascinating cell type.
authors.affiliation: Carl-Ludwig-Institute for Physiology, University of Leipzig, Leipzig, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Besser
authors.affiliation: Carl-Ludwig-Institute for Physiology, University of Leipzig, Leipzig, Germany.
authors.forename: Marit
authors.initials: M
authors.lastname: Sicker
authors.affiliation: Carl-Ludwig-Institute for Physiology, University of Leipzig, Leipzig, Germany.
authors.forename: Grit
authors.initials: G
authors.lastname: Marx
authors.affiliation: Carl-Ludwig-Institute for Physiology, University of Leipzig, Leipzig, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Winkler
authors.affiliation: Institute for Biochemistry and Molecular Medicine, University of Erlangen, Erlangen, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Eulenburg
authors.affiliation: Laboratory for Experimental Neuroanesthesiology, Clinic for Anesthesiology, University Hospital Göttingen, Göttingen, Germany; Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany.
authors.forename: Swen
authors.initials: S
authors.lastname: Hülsmann
authors.affiliation: Carl-Ludwig-Institute for Physiology, University of Leipzig, Leipzig, Germany; Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Hirrlinger
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002490:Central Nervous System / Q000166:cytology / Q000378:metabolism*; D005260:Female; D059330:GABAergic Neurons / Q000166:cytology / Q000378:metabolism*; D005968:Glutamate Decarboxylase / Q000235:genetics / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D037121:Plant Lectins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*; D000097573:Red Fluorescent Protein
chemical_list: D005968:Glutamate Decarboxylase; D008164:Luminescent Proteins; D037121:Plant Lectins; D012333:RNA, Messenger; D005680:gamma-Aminobutyric Acid; D000097573:Red Fluorescent Protein; C034981:tomato lectin