Abstract
Purpose :
Primary cilia are membranous cell-surface organelles with diverse functions such as cell cycle regulation, growth and differentiation, and mechanosensation. Genetic defects in cilia formation or maintenance have been implicated in many diseases, including renal cysts and retinitis pigmentosa. The presence of cilia in various ocular tissues are not well characterized. The goal of this study is to characterize primary cilia in ocular tissues using a ciliaGFP mouse model.
Methods :
CiliaGFP mouse model was previously established by crossing EIIa-cre with ROSA26Sstr3::GFP in C57BL/6 backgound. Enucleated eyes were dissected under a stereomicroscope. Confocal microscopy was performed to investigate the presence of cilia and the cilia length variety between different ocular tissues by quantification using Zeiss and NIH ImageJ. ScaleS was performed to optimize eyeball clearing, and to facilitate confocal imaging of cilia in ocular tissue in situ. Three-dimentional reconstruction of cilia in trabecular meshwork cells was performed under laminar flow conditions.
Results :
Multiple cilia were present in the cornea, retina, ciliary body, and retinal pigmented epithelium (RPE) cells from 8 to 12 months old CiliaGFP mice (N=6). The cilia length was 1.90±0.41µm (mean±SD) in the cornea (N>200) in a 8-month old mouse, compared to 1.41±0.41µm (N>40) in a 11-month old mice. The cilia were observed along the anterior surface of the iris and found to be 1.70±0.29µm (N>300) in a 11-month old mouse. Cilia were observed in the nonpigmented and pigmented ciliary epithelial cells as well as in the photoreceptors. RPE cells exhibited positive ciliaGFP signals.
Conclusions :
The CiliaGFP mouse model enabled us to examine the presence of primary cilia in multiple ocular tissues. The CiliaGFP mouse can be a powerful model for the study of physiologic functions of cilia in vivo.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.