Effects of retinoic acid upon eye field morphogenesis and differentiation.
This study describes a whole embryo and embryonic field analysis of retinoic acid's (RA) effects upon Xenopus laevis forebrain development and differentiation. By using in situ and immunohistochemical analysis of pax6, Xbf1, and tyrosine hydroxylase (TH), gene expression during eye field, telencephalon field, and retinal development was followed with and without RA treatment. These studies indicated that RA has strong effects upon embryonic eye and telencephalon field development with greater effects upon the ventral development of these organ fields. The specification and determination of separate eye primordia occurred at stage-16 when the prechordal plate reaches its most anterior aspect in Xenopus laevis. Differentiation of the dopaminergic cells within the retina was also affected in a distinct dorsoventral pattern by RA treatment, and cell type differentiation in the absence of distinct retinal laminae was also observed. It was concluded that early RA treatments affected organ field patterning by suppression of the upstream elements required for organ field development, and RA's effects upon cellular differentiation occur downstream to these organ determinants' expression within a distinct dorsoventral pattern.
Eagleson
G W
GW
Department of Biology, Loras College, Dubuque, Iowa 52004-1078, USA. eaglegw@loras.edu
Johnson-Meeter
L J
LJ
Frideres
J
J
D000818:Animals; D002454:Cell Differentiation; D004298:Dopamine; D005123:Eye / Q000187:drug effects / Q000196:embryology*; D005136:Eye Proteins; D020869:Gene Expression Profiling; D018398:Homeodomain Proteins / Q000235:genetics; D009024:Morphogenesis / Q000187:drug effects; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D016548:Prosencephalon / Q000196:embryology; D012097:Repressor Proteins; D013687:Telencephalon / Q000187:drug effects / Q000196:embryology; D014157:Transcription Factors / Q000235:genetics; D014212:Tretinoin / Q000378:metabolism* / Q000494:pharmacology; D029867:Xenopus Proteins; D014982:Xenopus laevis / Q000196:embryology
D005136:Eye Proteins; C117087:FOXG1 protein, Xenopus; D018398:Homeodomain Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins; D014157:Transcription Factors; D029867:Xenopus Proteins; D014212:Tretinoin; D004298:Dopamine