title: Localization of BDNF expression in the developing brain of zebrafish.
abstract: The brain-derived neurotrophic factor (BDNF) gene is expressed in differentiating and post-mitotic neurons of the zebrafish embryo, where it has been implicated in Huntington's disease. Little is known, however, about the full complement of neuronal cell types that express BDNF in this important vertebrate model. Here, we further explored the transcriptional profiles during the first week of development using real-time quantitative polymerase chain reaction (RT-qPCR) and whole-mount in situ hybridization (WISH). RT-qPCR results revealed a high level of maternal contribution followed by a steady increase of zygotic transcription, consistent with the notion of a prominent role of BDNF in neuronal maturation and maintenance. Based on WISH, we demonstrate for the first time that BDNF expression in the developing brain of zebrafish is structure specific. Anatomical criteria and co-staining with genetic markers (shh, pax2a, emx1, krox20, lhx2b and lhx9) visualized major topological domains of BDNF-positive cells in the pallium, hypothalamus, posterior tuberculum and optic tectum. Moreover, the relative timing of BDNF transcription in the eye and tectum may illustrate a mechanism for coordinated development of the retinotectal system. Taken together, our results are compatible with a local delivery and early role of BDNF in the developing brain of zebrafish, adding basic knowledge to the study of neurotrophin functions in neural development and disease.
authors.affiliation: Laboratory of Cellular and Developmental Biology, Stazione Zoologica Anton Dohrn, Naples, Italy; Department of Morphology, Biochemistry, Physiology and Animal Productions, Section of Morphology, University of Messina, Messina, Italy.
authors.forename: E
authors.initials: E
authors.lastname: De Felice
authors.forename: I
authors.initials: I
authors.lastname: Porreca
authors.forename: E
authors.initials: E
authors.lastname: Alleva
authors.forename: P
authors.initials: P
authors.lastname: De Girolamo
authors.forename: C
authors.initials: C
authors.lastname: Ambrosino
authors.forename: E
authors.initials: E
authors.lastname: Ciriaco
authors.forename: A
authors.initials: A
authors.lastname: Germanà
authors.forename: P
authors.initials: P
authors.lastname: Sordino
mesh_terms: D000818:Animals; D001921:Brain / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D009474:Neurons / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015027:Zebrafish
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D012333:RNA, Messenger
keywords: brain-derived neurotrophic factor; central nervous system; development; real-time quantitative polymerase chain reaction; whole-mount in situ hybridization; zebrafish