Equivalence in the genetic control of hindbrain segmentation in fish and mouse.
The vertebrate hindbrain is subdivided into a series of rhombomeres whose segmental organization serves to pattern the architecture and innervation of the developing head. The zebrafish gene valentino is required cell-autonomously in the development of rhombomeres 5 and 6, and valentino mutants lack visible hindbrain segmentation caudal to the r3/4 boundary (Moens, C. B., Yan, Y.-L., Appel, B., Force, A. G., and Kimmel, C. B. (1996) Development 122, 3981-3990). Here we show that valentino is the zebrafish homologue of the mouse segmentation gene kreisler, which encodes a bZip transcription factor. The valentino gene is expressed in a manner consistent with its proposed role in subdividing rhombomeres 5 and 6 from their common precursor 'proto-segment' in the presumptive hindbrain, a process that we also demonstrate is reflected in the normal order of appearance of rhombomere boundaries. As well as having similar phenotypes with respect to visible hindbrain segmentation and patterns of marker gene expression, valentino and kreisler mutants have similar pharyngeal arch and inner ear defects, consistent with a conserved role for this gene in hindbrain segmentation and in patterning of the head periphery.
Moens
C B
CB
Institute of Neuroscience, University of Oregon, Eugene 97403-1254, USA. moens@uoneuro.uregon.edu
Cordes
S P
SP
Giorgianni
M W
MW
Barsh
G S
GS
Kimmel
C B
CB
D000595:Amino Acid Sequence; D000818:Animals; D030161:Avian Proteins; D019521:Body Patterning / Q000235:genetics*; D001934:Branchial Region / Q000196:embryology; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics; D007758:Ear, Inner / Q000196:embryology; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D005796:Genes / Q000235:genetics; D016350:Leucine Zippers; D050977:Maf Transcription Factors; D051258:MafB Transcription Factor; D051379:Mice; D008969:Molecular Sequence Data; D009030:Mosaicism; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000502:physiology; D015513:Oncogene Proteins; D012150:Polymorphism, Restriction Fragment Length; D012333:RNA, Messenger / Q000032:analysis; D012249:Rhombencephalon / Q000196:embryology*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D019170:Somites / Q000737:chemistry; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics; D015027:Zebrafish; D029961:Zebrafish Proteins
D030161:Avian Proteins; D004268:DNA-Binding Proteins; D050977:Maf Transcription Factors; D051258:MafB Transcription Factor; C490406:Mafb protein, mouse; D009419:Nerve Tissue Proteins; D015513:Oncogene Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D029961:Zebrafish Proteins; C111092:mafb protein, zebrafish; C490408:mafbb protein, zebrafish