title: Cryptic organisation within an apparently irregular rostrocaudal distribution of interneurons in the embryonic zebrafish spinal cord.
abstract: The molecules and mechanisms involved in patterning the dorsoventral axis of the developing vertebrate spinal cord have been investigated extensively and many are well known. Conversely, knowledge of mechanisms patterning cellular distributions along the rostrocaudal axis is relatively more restricted. Much is known about the rostrocaudal distribution of motoneurons and spinal cord cells derived from neural crest but there is little known about the rostrocaudal patterning of most of the other spinal cord neurons. Here we report data from our analyses of the distribution of dorsal longitudinal ascending (DoLA) interneurons in the developing zebrafish spinal cord. We show that, although apparently distributed irregularly, these cells have cryptic organisation. We present a novel cell-labelling technique that reveals that DoLA interneurons migrate rostrally along the dorsal longitudinal fasciculus of the spinal cord during development. This cell-labelling strategy may be useful for in vivo analysis of factors controlling neuron migration in the central nervous system. Additionally, we show that DoLA interneurons persist in the developing spinal cord for longer than previously reported. These findings illustrate the need to investigate factors and mechanisms that determine "irregular" patterns of cell distribution, particularly in the central nervous system but also in other tissues of developing embryos.
authors.affiliation: Discipline of Genetics, School of Molecular and Biomedical Sciences, University of Adelaide, Adelaide, South Australia 5005, Australia. simon.wells@adelaide.edu.au
authors.forename: Simon
authors.initials: S
authors.lastname: Wells
authors.forename: John G
authors.initials: JG
authors.lastname: Conran
authors.forename: Richard
authors.initials: R
authors.lastname: Tamme
authors.forename: Arnaud
authors.initials: A
authors.lastname: Gaudin
authors.forename: Jonathan
authors.initials: J
authors.lastname: Webb
authors.forename: Michael
authors.initials: M
authors.lastname: Lardelli
mesh_terms: D000818:Animals; D019521:Body Patterning; D002449:Cell Aggregation; D002465:Cell Movement; D004625:Embryo, Nonmammalian / Q000166:cytology*; D007395:Interneurons / Q000166:cytology*; D008648:Mesoderm / Q000166:cytology; D019170:Somites / Q000166:cytology / Q000196:embryology; D013116:Spinal Cord / Q000166:cytology* / Q000196:embryology*; D020825:T-Box Domain Proteins / Q000378:metabolism; D013997:Time Factors; D015027:Zebrafish / Q000196:embryology*; D029961:Zebrafish Proteins / Q000378:metabolism
chemical_list: D020825:T-Box Domain Proteins; D029961:Zebrafish Proteins; C112539:tbx16 protein, zebrafish