Six3 inactivation reveals its essential role for the formation and patterning of the vertebrate eye.
The establishment of retinal identity and the subsequent patterning of the optic vesicle are the key steps in early vertebrate eye development. To date little is known about the nature and interaction of the genes controlling these steps. So far few genes have been identified that, when over-expressed, can initiate ectopic eye formation. Of note is Six3, which is expressed exclusively in the anterior neural plate. However, 'loss of function' analysis has not been reported. Using medaka fish, we show that vertebrate Six3 is necessary for patterning of the anterior neuroectoderm including the retina anlage. Inactivation of Six3 function by morpholino knock-down results in the lack of forebrain and eyes. Corroborated by gain-of-function experiments, graded interference reveals an additional role of Six3 in the proximodistal patterning of the optic vesicle. During both processes of vertebrate eye formation, Six3 cooperates with Pax6.
Carl
Matthias
M
Developmental Biology Programme, EMBL-Heidelberg, Meyerhofstr. 1, Germany.
Loosli
Felix
F
Wittbrodt
Joachim
J
D000818:Animals; D019521:Body Patterning; D004475:Ectoderm / Q000502:physiology; D004843:Epistasis, Genetic; D005123:Eye / Q000196:embryology*; D005136:Eye Proteins; D029941:Fish Proteins; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000502:physiology*; D009479:Neuropeptides / Q000378:metabolism; D009990:Oryzias; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D016548:Prosencephalon / Q000196:embryology; D012097:Repressor Proteins; D000097607:Homeobox Protein SIX3
D005136:Eye Proteins; D029941:Fish Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins; D000097607:Homeobox Protein SIX3; C121293:Rx3 protein, Oryzias latipes