Immunolocalization of ciliary neurotrophic factor receptor alpha (CNTFRalpha) in mammalian photoreceptor cells.
OBJECTIVE
To characterize the site of expression of the alpha subunit of the receptor for ciliary neurotrophic factor (CNTFRalpha) in the retina of a variety of mammalian species, and determine whether CNTFRalpha is localized to photoreceptor cells.


METHODS
The cellular distribution of CNTFRalpha(protein) was examined by immunocytochemistry in the adult retinas of several mammalian species that included mouse, rat, dog, cat, sheep, pig, horse, monkey, and human. Developing retinas from 3-day-old and 6-day-old rats were also included in this study. The molecular weight of CNTFRalpha in rat, dog, cat, pig, and human retinas was determined by immunoblotting.


RESULTS
CNTFRalpha immunolabeling was present in the retina of all species. A common pattern was observed in all species, and represented labeling of the nerve fiber layer (NFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), and outer plexiform layer (OPL). CNTFRalpha did not immunolocalize to photoreceptor cells in both adult and developing rodent retinas, but was consistently observed in both rods and cones of non-rodent species. The molecular weight of CNTFRalpha in mammalian retinas was approximately 61-64 kDa.


CONCLUSIONS
These findings highlight a significant difference in the expression of CNTFRalpha in the retina of rodent and non-rodent mammalian species. The expression of CNTFRalpha by rods and cones in non-rodent species may suggest a direct mechanism of action if CNTF administration results in photoreceptor rescue.
Beltran
William A
WA
James A. Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
Rohrer
Hermann
H
Aguirre
Gustavo D
GD
D000818:Animals; D015153:Blotting, Western; D002415:Cats; D004285:Dogs; D019084:Fluorescent Antibody Technique, Indirect; D006736:Horses; D006801:Humans; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D008252:Macaca fascicularis; D008253:Macaca mulatta; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008875:Middle Aged; D008970:Molecular Weight; D009412:Nerve Fibers / Q000378:metabolism; D020419:Photoreceptor Cells, Vertebrate / Q000378:metabolism*; D051381:Rats; D011917:Rats, Inbred Lew; D020801:Receptor, Ciliary Neurotrophic Factor / Q000378:metabolism*; D012165:Retinal Ganglion Cells / Q000378:metabolism; D012756:Sheep
D020801:Receptor, Ciliary Neurotrophic Factor