Seth Pranav Kumar, Heyers Dominik, Satish Baladev, Mendoza Ezequiel, Haase Katrin, Borowsky Lisa, Musielak Isabelle, Koch Karl-Wilhelm, Feederle Regina, Scharff Constance, Dedek Karin, Mouritsen Henrik
Neurosensorics Group/Animal Navigation, Institute of Biology and Environmental Sciences, Carl on Ossietzky University of Oldenburg, Oldenburg, Germany.
Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, United Kingdom.
Front Physiol. 2025 Mar 19;16:1549585. doi: 10.3389/fphys.2025.1549585. eCollection 2025.
Genetic manipulation of murine retinal tissue through ocular administration of adeno-associated viruses (AAVs) has become a standard technique to investigate a multitude of mechanisms underlying retinal physiology. Resultantly, developments of recombinant viral vectors with improved transduction efficiency and further methodological improvements have mostly focused on murine tissue, whereas AAVs successfully targeting avian retinae have remained scarce.
Using a custom-designed injection setup, we identified a viral serotype with the capability to successfully induce widespread transduction of the bird retina.
Intravitreal administration of an AAV type 2/9 encoding for enhanced green fluorescent protein (EGFP) in night-migratory European robins () resulted in transduction coverages of up to 60% within retinal tissue. Subsequent immunohistochemical analyses revealed that the AAV2/9-EGFP serotype almost exclusively targeted photoreceptors: rods, various single cones (UV, blue, green, and red cones), and both (accessory and principal) members of double cones.
The consistently high and photoreceptor-specific transduction efficiency makes the AAV2/9 serotype a powerful tool for carrying out genetic manipulations in avian retinal photoreceptors, thus opening a wealth of opportunities to investigate physiological aspects underlying retinal processing in birds, such as physiological recordings and/or post-transductional behavioural readouts for future vision-related research.
通过眼内注射腺相关病毒（AAV）对小鼠视网膜组织进行基因操作已成为研究视网膜生理多种潜在机制的标准技术。因此，提高转导效率的重组病毒载体的开发以及进一步的方法改进大多集中在小鼠组织上，而成功靶向鸟类视网膜的AAV仍然很少。
使用定制设计的注射装置，我们鉴定出一种能够成功诱导鸟类视网膜广泛转导的病毒血清型。
在夜间迁徙的欧洲知更鸟（Erithacus rubecula）眼内注射编码增强型绿色荧光蛋白（EGFP）的2/9型AAV，导致视网膜组织内的转导覆盖率高达60%。随后的免疫组织化学分析表明，AAV2/9-EGFP血清型几乎只靶向光感受器：视杆细胞、各种单视锥细胞（紫外、蓝色、绿色和红色视锥细胞）以及双视锥细胞的两个成员（辅助视锥细胞和主视锥细胞）。
持续高且光感受器特异性的转导效率使AAV2/9血清型成为在鸟类视网膜光感受器中进行基因操作的有力工具，从而为研究鸟类视网膜处理的生理方面，如未来视觉相关研究的生理记录和/或转导后行为读数，开辟了大量机会。
