Exceptional Visual-Opsin Coexpression and Phenotypic Diversity in Outer-Retinal Photoreceptors of Caenophidian Snakes.

ABSTRACT: Snakes are a valuable yet understudied taxon for investigating evolutionary adaptations in the vertebrate retina. They possess up to three visual pigments: a short-wavelength-sensitive opsin (SWS1), a medium/long-wavelength-sensitive opsin (LWS), and rhodopsin (RH1). Nocturnal snakes have duplex retinas containing both rod and cone photoreceptors, whereas diurnal caenophidian ("advanced") snakes exhibit simplex "all-cone" retinas, lacking morphologically typical rods. In this study, we analyzed photoreceptor morphology in the retinas of caenophidian snakes using high-resolution scanning electron microscopy (SEM) and examined visual-opsin expression patterns with immunohistochemistry (IHC). Our analyses revealed remarkable interspecific variability in visual-cell morphology. Light microscop

SUBMITTER: Hauzman E 

PROVIDER: S-EPMC12501914 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature