Retina dorsal/ventral patterning by Xenopus TBX3.
Although it is well known that patterning in the retina of vertebrates is essential for retina formation and for the retinotopic projection of axons in the embryo, knowledge of molecular and cellular mechanisms of retina patterning is limited. We have previously identified the Xenopus Tbx3 gene (XTbx3) which is expressed in the dorsal retina but not in the ventral retina in Xenopus embryos [H. Li, C. Tierney, L. Wen, J. Y. Wu, and Y. Rao (1997) Development 124, 603-615; M.-L. He, L. Wen, C. E. Campbell, J. Y. Wu, and Y. Rao (1999) Proc. Natl. Acad. Sci. USA 96, 10212-10217]. Dosage-sensitive phenotypes in humans suggest that the manipulation of the amount and location of its products could be informative for understanding its normal function. Here we report that ectopic expression of Tbx3 by mRNA injection suppressed formation of the ventral retina. Furthermore, Tbx3 injection led to inhibition of molecular markers for the ventral retina including Pax-2 and netrin, indicating that Tbx3 plays an important role in retina dorsal/ventral patterning in vertebrates by inhibition of gene expression for ventral retina specification.
Wong
Kit
K
Department of Anatomy and Neurobiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, Missouri 63110, USA.
Peng
Ying
Y
Kung
Hsiang-fu
HF
He
Ming-Liang
ML
D000818:Animals; D000943:Antigens, Differentiation / Q000378:metabolism; D019521:Body Patterning / Q000187:drug effects / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000002:abnormalities / Q000166:cytology; D008845:Microinjections; D009414:Nerve Growth Factors / Q000037:antagonists & inhibitors / Q000378:metabolism; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D051762:PAX2 Transcription Factor; D010641:Phenotype; D012333:RNA, Messenger / Q000008:administration & dosage / Q000378:metabolism; D012160:Retina / Q000002:abnormalities* / Q000166:cytology / Q000378:metabolism*; D020825:T-Box Domain Proteins / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000378:metabolism; D029867:Xenopus Proteins; D014982:Xenopus laevis
D000943:Antigens, Differentiation; D004268:DNA-Binding Proteins; D009414:Nerve Growth Factors; D051762:PAX2 Transcription Factor; D012333:RNA, Messenger; D020825:T-Box Domain Proteins; C491459:Tbx3 protein, Xenopus; D014157:Transcription Factors; D029867:Xenopus Proteins