Immunohistochemical study of pig retinal development.
OBJECTIVE
The pig eye is similar to the human eye in terms of anatomy, vasculature, and photoreceptor distribution, and therefore provides an attractive animal model for research into retinal disease. The purpose of this study was to characterize retinal histology in the developing and mature pig retina using antibodies to well established retinal cell markers commonly used in rodents.


METHODS
Eyes were enucleated from fetuses in the 9th week of gestation, 1 week old piglets and 6 months old adult animals. Eyeglobes were fixed and cryosectioned. A panel of antibodies to well established retinal markers was employed for immunohistochemistry. Fluorescently labeled secondary antibodies were used for signal detection, and images were acquired by confocal microscopy. Mouse retina at postnatal day (P) 5 was used as a reference for this study to compare progression of histogenesis. Most of the primary antibodies have previously been used on mouse tissue.


RESULTS
Most of the studied markers were detected in midgestation pig retina, and the majority had a similar distribution in pig as in P5 mouse retina. However, rhodopsin immunolabeling was detected in pig retina at midgestation but not in P5 mouse retina. Contrary to findings in all rodents, horizontal cells were Islet1-positive and cones were calbindin-immunoreactive in pig retina, as has also been shown for the primate retina. Recoverin and rhodopsin immunolabeling revealed an increase in the length of photoreceptor segments in 6 months, compared to 1 week old animals.


CONCLUSIONS
Comparison with the published data on human retina revealed similar marker distribution and histogenesis progression in the pig and human retina, supporting the pig as a valuable animal model for studies on retinal disease and repair. Furthermore, this study provides information about the dynamics of retinal histogenesis in the pig and validates a panel of antibodies that reliably detects developing and mature retinal cell phenotypes in the pig retina.
Guduric-Fuchs
Jasenka
J
Centre for Vision and Vascular Sciences, Queen's University Belfast, United Kingdom. j.guduricfuchs@qub.ac.uk
Ringland
Laura J
LJ
Gu
Ping
P
Dellett
Margaret
M
Archer
Desmond B
DB
Cogliati
Tiziana
T
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D064032:Calbindin 2; D064026:Calbindins; D016616:Cryoultramicrotomy; D005136:Eye Proteins / Q000378:metabolism; D005968:Glutamate Decarboxylase / Q000378:metabolism; D018398:Homeodomain Proteins / Q000378:metabolism; D007150:Immunohistochemistry; D007381:Intermediate Filament Proteins / Q000378:metabolism; D019394:Ki-67 Antigen / Q000378:metabolism; D060850:LIM-Homeodomain Proteins; D051379:Mice; D023421:Models, Animal; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D009457:Neuroglia / Q000166:cytology / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000378:metabolism; D020419:Photoreceptor Cells, Vertebrate / Q000166:cytology / Q000378:metabolism; D051571:Protein Kinase C-alpha / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D012160:Retina / Q000166:cytology / Q000201:enzymology / Q000254:growth & development* / Q000378:metabolism*; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D034421:Sus scrofa; D014157:Transcription Factors
D015415:Biomarkers; D064032:Calbindin 2; D064026:Calbindins; D005136:Eye Proteins; D018398:Homeodomain Proteins; D007381:Intermediate Filament Proteins; D019394:Ki-67 Antigen; D060850:LIM-Homeodomain Proteins; C577484:NES protein, human; D009419:Nerve Tissue Proteins; C577485:Nes protein, mouse; D064231:Nestin; D009687:Nuclear Proteins; D000071841:PAX6 Transcription Factor; C000605730:PAX6 protein, human; D051761:Paired Box Transcription Factors; C000605732:Pax6 protein, mouse; D012097:Repressor Proteins; D064030:S100 Calcium Binding Protein G; D014157:Transcription Factors; C063843:insulin gene enhancer binding protein Isl-1; D051571:Protein Kinase C-alpha; D005968:Glutamate Decarboxylase; C401141:glutamate decarboxylase 2