1：Experimental Design and Method Selection:

The study used a transgenic mouse model (SCA7 R7E mice) expressing human ataxin7 with a polyglutamine expansion to investigate retinal degeneration. Methods included genotyping, immunohistochemistry, TUNEL staining, Western blot analysis, intravitreous injections of siRNA and inhibitors, and cell culture experiments with HEK293 cells.

2：Sample Selection and Data Sources:

SCA7 R7E mice on a C57/Bl6 background were used, with samples collected at postnatal 5 weeks. Human Embryonic Kidney 293 (HEK293) cells stably transfected with wild-type or mutant ataxin7 were also used.

3：List of Experimental Equipment and Materials:

Equipment included a Leica CM3050 S freezing microtome, fluorescent microscope (Olympus U-25ND25), Micro4 micro-injector (World Precision Instruments), Cytospin-4 (Thermo Scientific), and various kits and reagents such as Kapa Express Extract kit, Kapa2G Robust Hotstart Ready Mix PCR kit, Tissue-Tek O.C.T., antibodies (listed in Table 1), and chemicals like DAPI, Triton X-100, and protease inhibitors.

4：Experimental Procedures and Operational Workflow:

Mice were genotyped, sacrificed, and eyes processed for frozen sections or protein extraction. Immunohistochemistry and TUNEL staining were performed with specific protocols, including dephosphorylation steps. Western blotting was used for protein analysis. Intravitreous injections of siRNA (siCtrl, siLEI, siAIF) and inhibitors (Calpain Inhibitor VI, Pepstatin A) were administered, and cell death was quantified. HEK293 cells were cultured and induced for transgene expression, followed by immunocytochemistry.

5：Data Analysis Methods:

Statistical analysis was performed using GraphPad Prism software with non-parametric tests (Mann-Whitney, Kruskal-Wallis with Dunn's post-test). Image analysis used ImageJ software for quantification.