title: Regulation and function of Dbx genes in the zebrafish spinal cord.
abstract: Dbx homeodomain proteins are important for spinal cord dorsal/ventral patterning and the production of multiple spinal cord cell types. We have examined the regulation and function of Dbx genes in the zebrafish. We report that Hedgehog signaling is not required for the induction or maintenance of these genes; in the absence of Hedgehog signaling, dbx1a/1b/2 are expanded ventrally with concomitant increases in postmitotic neurons that differentiate from this domain. Also, we find that retinoic acid signaling is not required for the induction of Dbx expression. Furthermore, we are the first to report that knockdown of Dbx1 function causes a dorsal expansion of nkx6.2, which is thought to be the cross-repressive partner of Dbx1 in mouse. Our data confirm that the dbx1a/1b/2 domain in zebrafish spinal cord development behaves similarly to amniotes, while extending knowledge of Dbx1 function in spinal cord patterning.
authors.affiliation: Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah 84132-3401, USA.
authors.forename: Suzanna L
authors.initials: SL
authors.lastname: Gribble
authors.forename: O Brant
authors.initials: OB
authors.lastname: Nikolaus
authors.forename: Richard I
authors.initials: RI
authors.lastname: Dorsky
mesh_terms: D000818:Animals; D001483:Base Sequence; D019521:Body Patterning / Q000235:genetics; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox; D053823:Hedgehog Proteins / Q000235:genetics / Q000378:metabolism; D018398:Homeodomain Proteins / Q000037:antagonists & inhibitors / Q000235:genetics; D009457:Neuroglia / Q000166:cytology / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D020319:Oligodeoxyribonucleotides, Antisense / Q000235:genetics; D015398:Signal Transduction; D013116:Spinal Cord / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics; D014212:Tretinoin / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics* / Q000378:metabolism; D029961:Zebrafish Proteins / Q000037:antagonists & inhibitors / Q000235:genetics
chemical_list: D053823:Hedgehog Proteins; D018398:Homeodomain Proteins; D020319:Oligodeoxyribonucleotides, Antisense; D014157:Transcription Factors; D029961:Zebrafish Proteins; C490000:dbx1a protein, zebrafish; C490001:dbx1b protein, zebrafish; C490002:dbx2 protein, zebrafish; D014212:Tretinoin