Adaptations and evolutionary trajectories of the snake rod and cone photoreceptors

Autor(es)

Hauzman, Einat

• Tipo de documento: Artigo Científico
• Fonte: SEMINARS IN CELL & DEVELOPMENTAL BIOLOGY; v. 106, p. 8-pg., 2020-10-01.

Resumo

Most vertebrates have duplex retinas, with two classes of photoreceptors, rods and cones. In the group of Snakes, however, distinct patterns of retinal morphology are associated with transitions between diurnal-nocturnal habits and reflect important adaptations of their visual system. Pure-cone, pure-rod and duplex retinas were described in different species, and this variability led Gordon Walls (1934) to formulate the transmutation theory, which suggests that rods and cones are not fixed entities, but can assume transitional states. Three opsin genes are expressed in retinas of most snake species, Iws, rh1, and sws1, and recent studies have shown that the rhodopsin gene, rh1, is expressed in pure-cone retinas of diurnal snakes. This expression raised many questions about the nature of transmutation and functional aspects of the rhodopsin in a cone-like photoreceptor. Extreme differences in the retinal architecture of diurnal and nocturnal snakes also highlight the complexity of adaptations of their visual structures, which might have contributed to the adaptive radiation of this group and will be discussed in this review. (AU)

• Processo FAPESP: 14/25743-9 - Expressão de opsinas e melanopsinas em retinas de serpentes: genética molecular e imunohistoquímica
• Beneficiário: Einat Hauzman
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 18/09321-8 - Expressão in vitro e medidas de absorção espectral do fotopigmento SWS1 da serpente colubridea Helicops modestus
• Beneficiário: Einat Hauzman
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado