title: Doublecortin and doublecortin-like are expressed in overlapping and non-overlapping neuronal cell population: implications for neurogenesis.
abstract: We have characterized the expression of doublecortin-like (DCL), a microtubule-associated protein involved in embryonic neurogenesis that is highly homologous to doublecortin (DCX), in the adult mouse brain. To this end, we developed a DCL-specific antibody and used this to compare DCL expression with DCX. In the neurogenic regions of the adult brain like the subventricular zone (SVZ), the rostral migratory stream (RMS), the olfactory bulb (OB), and the hippocampus, DCL colocalizes with DCX in immature neuronal cell populations. In contrast to DCX, we also found high DCL expression in three other brain regions with suspected neurogenesis or neuronal plasticity. First, the radial glia-like, hypothalamic tanycytes show high DCL expression that partly colocalizes with the neural stem cell marker vimentin. Second, DCL expression is found in cells of the suprachiasmatic nucleus (SCN), which lacks expression of the adult neuron marker NeuN. Third, a novel region exhibiting DCL expression is part of the olfactory tubercle where DCL is found in the neuropil of the islands of Calleja (ICj). Our findings define DCL as a novel marker for specific aspects of adult neurogenesis, which partly overlap with DCX. In addition, we propose unique roles for DCL in adult neurogenesis and we suggest high levels of neuronal plasticity in tanycytes, SCN, and ICj.
authors.affiliation: Department of Medical Pharmacology, Leiden University Medical Center, P.O. Box 9503, 2300 RA, Leiden, The Netherlands.
authors.forename: Dirk-Jan
authors.initials: DJ
authors.lastname: Saaltink
authors.forename: Bjarte
authors.initials: B
authors.lastname: Håvik
authors.forename: Carla S
authors.initials: CS
authors.lastname: Verissimo
authors.forename: P J
authors.initials: PJ
authors.lastname: Lucassen
authors.forename: Erno
authors.initials: E
authors.lastname: Vreugdenhil
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D000089742:Doublecortin-Like Kinases; D005455:Fluorescent Antibody Technique; D007150:Immunohistochemistry; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis*; D058953:Neural Stem Cells / Q000166:cytology / Q000378:metabolism; D055495:Neurogenesis / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009479:Neuropeptides / Q000096:biosynthesis*; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis*
chemical_list: C000714847:Dcx protein, mouse; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D008869:Microtubule-Associated Proteins; D009479:Neuropeptides; D000089742:Doublecortin-Like Kinases; C485525:Dclk1 protein, mouse; D017346:Protein Serine-Threonine Kinases