Related Experiment Video
Updated: Sep 13, 2025
09:53
Volumetric Imaging and Analysis of Primary Cilia in Musculoskeletal Tissue using the ARL13B-CENTRIN-2 Mouse Model
Published on: March 28, 2025
585
Ciliary ARL13B Is Essential for Vision and Morphogenesis of Cone Outer Segments
Alexis Crockett1, Sierra Kuzak2, Thamaraiselvi Saravanan2
1Departments of Neuroscience, West Virginia University, School of Medicine, Morgantown, West Virginia 26506.
Summary
ARL13B is crucial for photoreceptor cilia function, essential for vision. Its exclusion from cilia causes early cone vision loss and later rod vision decline, impacting retinal health.
Area of Science:
- Molecular Biology
- Cell Biology
- Ophthalmology
Background:
- Mutations in ARL13B cause Joubert syndrome, a ciliopathy affecting neurological and retinal tissues.
- ARL13B's role in photoreceptor cilia, particularly its function in maintaining vision, remains largely unknown.
- Photoreceptor cilia are vital for vision, and their dysfunction leads to retinal abnormalities.
Purpose of the Study:
- To investigate the specific function of ARL13B within photoreceptor cilia.
- To elucidate the role of ciliary ARL13B in maintaining photoreceptor structure and function.
- To understand the molecular mechanisms underlying ARL13B-related retinal abnormalities in Joubert syndrome.
Main Methods:
- Utilized a knock-in mouse model (Arl13b V358A) to specifically disrupt ciliary localization of ARL13B.
- Performed electroretinography (ERG) to assess photoreceptor function (rod and cone-mediated vision).
- Conducted immunohistochemistry (IHC) and transmission electron microscopy (TEM) for morphological and protein localization analyses.
Main Results:
- Exclusion of ARL13B from photoreceptor cilia caused early cone vision loss and subsequent rod vision decline.
- Morphological analysis revealed shortened cone axonemes and outer segment structural defects in the V358A model.
- Loss of ciliary ARL13B disrupted intraflagellar transport protein 88 (IFT88) localization and mislocalized Tubby-like protein 1 (TULP1).
Conclusions:
- Ciliary ARL13B is essential for maintaining cone photoreceptor axoneme length and outer segment organization.
- Proper localization of ARL13B within cilia is critical for photoreceptor function and protein trafficking.
- Findings highlight the importance of phosphoinositide gradients in cone photoreceptor health and suggest novel insights into ciliopathy pathogenesis.
Related Concept Videos
01:20Anatomy of the Eyeball
7.6K
The eye is a spherical, hollow structure composed of three tissue layers. The outer layer — the fibrous tunic, comprises the sclera — a white structure — and the cornea, which is transparent. The sclera encompasses some of the ocular surface, most of which is not visible. However, the 'white of the eye' is distinctively visible in humans compared to other species. The cornea, a clear covering at the front of the eye, enables light penetration. The eye's middle...
7.6K
01:22Microtubules in Signaling
1.8K
The primary cilium, made up of microtubules, acts as antennae on the cell surfaces for relaying external stimuli into the cells. These fine hair-like structures are present, generally one per cell. These are non-motile cilia in a 9+0 microtubules arrangement, where the central pair of microtubules are absent. The primary cilia arise from the basal body embedded in the cell membrane. Intraflagellar transport (IFT) carries requisite proteins from the cytoplasm to the cilium because the primary...
1.8K
01:05Mechanism of Ciliary Motion
3.9K
The ciliary structures were first seen in 1647 by Antonie Leeuwenhoek while observing the protozoans. In lower organisms, these appendages are responsible for cell movement, while in higher organisms, these appendages help in the movement of the extracellular fluids within the body cavities.
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
3.9K
01:22Photoreceptors and Visual Pathways
6.5K
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category,...
6.5K
01:32The Retina
70.6K
The retina is a layer of nervous tissue at the back of the eye that transduces light into neural signals. This process, called phototransduction, is carried out by rod and cone photoreceptor cells in the back of the retina.
70.6K
01:24Vision
55.3K
Vision is the result of light being detected and transduced into neural signals by the retina of the eye. This information is then further analyzed and interpreted by the brain. First, light enters the front of the eye and is focused by the cornea and lens onto the retina—a thin sheet of neural tissue lining the back of the eye. Because of refraction through the convex lens of the eye, images are projected onto the retina upside-down and reversed.
55.3K