Photoreceptor calyceal processes accompany the developing outer segment, adopting a stable length despite a dynamic core.
J Cell Sci
; 137(7)2024 Apr 01.
Article
in En
| MEDLINE
| ID: mdl-38477343
ABSTRACT
Vertebrate photoreceptors detect light through a large cilium-based outer segment, which is filled with photopigment-laden membranous discs. Surrounding the base of the outer segment are microvilli-like calyceal processes (CPs). Although CP disruption has been associated with altered outer segment morphology and photoreceptor degeneration, the role of the CPs remains elusive. Here, we used zebrafish as a model to characterize CPs. We quantified CP parameters and report a strong disparity in outer segment coverage between photoreceptor subtypes. CP length is stable across light and dark conditions, yet heat-shock inducible expression of tagged actin revealed rapid turnover of the CP actin core. Detailed imaging of the embryonic retina uncovered substantial remodeling of the developing photoreceptor apical surface, including a transition from dynamic tangential processes to vertically oriented CPs immediately prior to outer segment formation. Remarkably, we also found a direct connection between apical extensions of the Müller glia and retinal pigment epithelium, arranged as bundles around the ultraviolet sensitive cones. In summary, our data characterize the structure, development and surrounding environment of photoreceptor microvilli in the zebrafish retina.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Zebrafish
/
Actins
Limits:
Animals
Language:
En
Journal:
J Cell Sci
Year:
2024
Document type:
Article
Affiliation country:
Canada