- Generated immunodeficient RD rat strains: homozygous CAG-LSL-TdTomato (RNT) and Pcp2-Cre founders, crossbred to yield TdTomato-Pcp2 (RTP) rats.
- AAV-PHP.eB-hSyn-Cre induced TdTomato in RNT retinas; targeted Pcp2-Cre marked ON bipolar cells and cones, random insertions labelled additional cells.
- RTP rats recapitulate RhoS334ter-3 degeneration, define transplant-host boundaries, and provide a platform for cell therapy and cell-specific labelling studies.
Transl Vis Sci Technol. 2026 Aug 3;15(8):24. doi: 10.1167/tvst.15.8.24.
ABSTRACT
PURPOSE: The purpose of this study was to develop a fluorescently labeled immunodeficient retinal degenerate (RD) rat model for studying photoreceptor degeneration and transplant-host connectivity using the Cre-lox system.
METHODS: We developed gene constructs for CAG-LSL-TdTomato (expressing floxed TdTomato) and Pcp2-Cre (marker for ON-bipolar cells) that were injected into rat embryos. The LSL TdTomato reporter strain, created on immunodeficient RhoS334ter-3 rats (RRRC #539), was bred to homozygosity (strain SD-Foxn1rnuTg((Rho-S334X)3,CAG-TdTomato)1010Mjsuc, RRRC #1055, “RNT”). The gene construct Pcp2-Cre was injected into Long-Evans (LE) rat embryos, resulting in two Pcp2-cre founders (strain PCP2 Cre-1105 RKI, “Pcp2”), with targeted and targeted/random insertion of the transgene. F1 offspring were bred to homozygosity and immunodeficiency. To test whether TdTomato expression can be induced in “RNT” rats expressing floxed TdTomato, retinal explants of P9 “RNT” rats were exposed to AAV-PHP.eB-hSyn-myc-Cre (AAV-Syn-Cre) virus. Homozygous rats of both strains (“RNT” and Pcp2-Cre) were crossbred to generate RD TdTomato-Pcp2 (“RTP”) rats. Retinas were stained for various retinal markers. GFP-expressing rat retinas were transplanted to 6-week-old “RTP” rats and analyzed after 37 and 77 days.
RESULTS: AAV-Syn-Cre induced TdTomato expression in “RNT” retinas. TdTomato-Pcp2 RD rats developed RD similar to the original Rho S334ter-3 rats. Retinas with targeted Pcp2-Cre insertion showed TdTomato in retinal interneurons, overlapping with Pcp2-staining ON bipolar cells, and cones. Retinas with random Pcp2-Cre insertion exhibited additional TdTomato in many other cells. Pcp2-TdTomato expression defined transplant-host boundaries.
CONCLUSIONS: We created a unique RD rat model for studying retinal transplant connectivity which can also be used to generate RD rats with other cell-specific labels.
TRANSLATIONAL RELEVANCE: This newly created rat is useful for cell therapy and retinal degeneration studies.
PMID:42640160 | DOI:10.1167/tvst.15.8.24
Share Evidence Blueprint
Save to Google Notes
Search Google Scholar
Save as PDF
⭐ My Revision List
