Otx2 homeobox gene induces photoreceptor-specific phenotypes in cells derived from adult iris and ciliary tissue.
OBJECTIVE
It remains unclear which gene induction effectively generates photoreceptor-specific phenotypes from nonretinal tissues. The purpose of this study was to determine whether Crx and Otx2--homeobox genes related to photoreceptor development--can induce the generation of these phenotypes in cells derived from adult ciliary and iris tissue and in mesencephalon-derived neural stem cells.


METHODS
Crx and Otx2 were transferred into adult rat ciliary- and embryonic mesencephalon-derived neurospheres and adult rat iris-derived cells with the aid of a recombinant retrovirus. The presence of photoreceptor-specific phenotypes was confirmed by immunocytochemistry and Western blot analysis.


RESULTS
More than 90% of the Crx- and Otx2-transfected ciliary- and iris-derived cells exhibited rod opsin immunoreactivity, whereas few of the similarly transfected mesencephalon-derived neural stem cells expressed rod opsin. At least two additional key components of the phototransduction cascade, recoverin and Gdeltat1, were expressed by Crx- and Otx2-transfected iris-derived cells.


CONCLUSIONS
Crx and Otx2 effectively induced the generation of photoreceptor-specific phenotypes from ciliary- and iris-derived cells. That both Crx and Otx2 induced phenotype generation in cells derived from iris or ciliary tissue may suggest an approach to photoreceptor cell preparation for retinal transplantation.
Akagi
Tadamichi
T
Department of Ophthalmology and Visual Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Mandai
Michiko
M
Ooto
Sotaro
S
Hirami
Yasuhiko
Y
Osakada
Fumitaka
F
Kageyama
Ryoichiro
R
Yoshimura
Nagahisa
N
Takahashi
Masayo
M
D000818:Animals; D000941:Antigens / Q000378:metabolism; D015153:Blotting, Western; D002454:Cell Differentiation; D002478:Cells, Cultured; D002924:Ciliary Body / Q000166:cytology / Q000502:physiology*; D000939:Epitopes; D005260:Female; D018014:Gene Transfer Techniques; D005801:Genes, Homeobox; D018398:Homeodomain Proteins / Q000235:genetics* / Q000502:physiology; D015151:Immunoblotting; D007150:Immunohistochemistry; D007498:Iris / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D008636:Mesencephalon / Q000166:cytology; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000502:physiology; D009474:Neurons / Q000166:cytology; D051857:Otx Transcription Factors; D010641:Phenotype; D020419:Photoreceptor Cells, Vertebrate / Q000276:immunology / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D017208:Rats, Wistar; D018874:Spheroids, Cellular; D013234:Stem Cells / Q000166:cytology; D015534:Trans-Activators / Q000235:genetics* / Q000502:physiology
D000941:Antigens; D000939:Epitopes; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D051857:Otx Transcription Factors; D015534:Trans-Activators; C109288:cone rod homeobox protein