Dach1, a vertebrate homologue of Drosophila dachshund, is expressed in the developing eye and ear of both chick and mouse and is regulated independently of Pax and Eya genes.
We have cloned a chick homologue of Drosophila dachshund (dac), termed Dach1. Dach1 is the orthologue of mouse and human Dac/Dach (hereafter referred to as Dach1). We show that chick Dach1 is expressed in a variety of sites during embryonic development, including the eye and ear. Previous work has demonstrated the existence of a functional network and genetic regulatory hierarchy in Drosophila in which eyeless (ey, the Pax6 orthologue), eyes absent (eya), and dac operate together to regulate Drosophila eye development, and that ey regulates the expression of eya and dac. We find that in the developing eye of both chick and mouse, expression domains of Dach1 overlap with those of Pax6, a gene required for normal eye development. Similarly, in the developing ear of both mouse and chick, Dach1 expression overlaps with the expression of another Pax gene, Pax2. In the mouse, Dach1 expression in the developing ear also overlaps with the expression of Eya1 (an eya homologue). Both Pax2 and Eya1 are required for normal ear development. Our expression studies suggest that the Drosophila Pax-eya-dac regulatory network may be evolutionarily conserved such that Pax genes, Eya1, and Dach1 may function together in vertebrates to regulate neural development. To address the further possibility that a regulatory hierarchy exists between Pax, Eya, and Dach genes, we have examined the expression of mouse Dach1 in Pax6, Pax2 and Eya1 mutant backgrounds. Our results indicate that Pax6, Pax2, and Eya1 do not regulate Dach1 expression through a simple linear hierarchy.
Heanue
Tiffany A
TA
Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.
Davis
Richard J
RJ
Rowitch
David H
DH
Kispert
Andreas
A
McMahon
Andrew P
AP
Mardon
Graeme
G
Tabin
Clifford J
CJ
D000595:Amino Acid Sequence; D000818:Animals; D002642:Chick Embryo; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004330:Drosophila / Q000235:genetics; D029721:Drosophila Proteins; D004423:Ear / Q000002:abnormalities / Q000196:embryology / Q000254:growth & development*; D005123:Eye / Q000196:embryology*; D005136:Eye Proteins / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D008969:Molecular Sequence Data; D009420:Nervous System / Q000196:embryology; D009687:Nuclear Proteins / Q000235:genetics; D051762:PAX2 Transcription Factor; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D017027:Protein Tyrosine Phosphatases; D012097:Repressor Proteins; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
C486747:DACH1 protein, human; D004268:DNA-Binding Proteins; C456264:Dach1 protein, mouse; D029721:Drosophila Proteins; D005136:Eye Proteins; D018398:Homeodomain Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D051762:PAX2 Transcription Factor; C497318:PAX2 protein, human; D000071841:PAX6 Transcription Factor; C000605730:PAX6 protein, human; D051761:Paired Box Transcription Factors; C497319:Pax2 protein, mouse; C000605732:Pax6 protein, mouse; D012097:Repressor Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C103968:dac protein, Drosophila; C104381:EYA1 protein, human; C501156:Eya1 protein, mouse; D017027:Protein Tyrosine Phosphatases