Pax6 modulates the dorsoventral patterning of the mammalian telencephalon.
The Pax6 gene encodes a transcription factor with a restricted expression in the ventricular zone of the pallium and subpallium. We tested whether the function of Pax6 is necessary for the correct patterning and morphogenesis of the vertebrate telencephalon. Homozygous embryos of the Pax6/Small eye mutant lack functional PAX6 protein because of a point mutation of the gene. In the mutant Small eye embryos we detected a ventralization of the molecular patterning of the telencephalon at two borders, the pallium/subpallium and the lateral/medial ganglionic eminence. The results indicate that Pax6 controls the lateral limit of the expression of Nkx2.1, Shh, and Lhx6 in the prechordal neural tube, the telencephalon. This finding is in agreement with previous studies and supports a model for a common genetic mechanism for modulation of the dorsoventral patterning of the prechordal and epichordal CNS. The pattern defects caused by the loss of Pax6 function result in multiple morphological abnormalities in the Small eye brain: dysgenesis of the piriform, insular, and lateral cortices, the claustrum-endopiriform nucleus, and a failure in the differentiation of a subpopulation of the cortical precursors. Together the results demonstrate that Pax6 has an essential role for the modulation of the dorsoventral patterning of the embryonic telencephalon, influencing thereby the forebrain morphogenesis.
Stoykova
A
A
Max-Planck Institute of Biophysical Chemistry, Department of Molecular Cell Biology, 37077 Göttingen, Germany. astoyko@gwdg.de
Treichel
D
D
Hallonet
M
M
Gruss
P
P
D000818:Animals; D000943:Antigens, Differentiation / Q000096:biosynthesis; D019521:Body Patterning / Q000187:drug effects / Q000502:physiology*; D015816:Cell Adhesion Molecules, Neuronal / Q000096:biosynthesis; D002454:Cell Differentiation / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D004848:Epithelium / Q000196:embryology; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis; D005136:Eye Proteins; D018398:Homeodomain Proteins / Q000378:metabolism* / Q000494:pharmacology; D006720:Homozygote; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D060850:LIM-Homeodomain Proteins; D051379:Mice; D008817:Mice, Mutant Strains; D009419:Nerve Tissue Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D000091042:Reelin Protein; D012097:Repressor Proteins; D012697:Serine Endopeptidases; D013687:Telencephalon / Q000187:drug effects / Q000196:embryology* / Q000378:metabolism; D014157:Transcription Factors
D000943:Antigens, Differentiation; D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; D005136:Eye Proteins; D018398:Homeodomain Proteins; C498504:LHX6 protein, mouse; D060850:LIM-Homeodomain Proteins; D009419:Nerve Tissue Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; C000605732:Pax6 protein, mouse; D000091042:Reelin Protein; D012097:Repressor Proteins; D014157:Transcription Factors; D012697:Serine Endopeptidases