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Phototransduction in Anuran Green Rods: Origins of Extra-Sensitivity
Green rods (GRs) represent a unique type of photoreceptor to be found in the retinas of anuran amphibians. These cells harbor a cone-specific blue-sensitive visual pigment but exhibit morphology of the outer segment typical for classic red rods (RRs), which makes them a perspective model object for...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8707487/ https://www.ncbi.nlm.nih.gov/pubmed/34948198 http://dx.doi.org/10.3390/ijms222413400 |
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author | Astakhova, Luba A. Novoselov, Artem D. Ermolaeva, Maria E. Firsov, Michael L. Rotov, Alexander Yu. |
author_facet | Astakhova, Luba A. Novoselov, Artem D. Ermolaeva, Maria E. Firsov, Michael L. Rotov, Alexander Yu. |
author_sort | Astakhova, Luba A. |
collection | PubMed |
description | Green rods (GRs) represent a unique type of photoreceptor to be found in the retinas of anuran amphibians. These cells harbor a cone-specific blue-sensitive visual pigment but exhibit morphology of the outer segment typical for classic red rods (RRs), which makes them a perspective model object for studying cone–rod transmutation. In the present study, we performed detailed electrophysiological examination of the light sensitivity, response kinetics and parameters of discrete and continuous dark noise in GRs of the two anuran species: cane toad and marsh frog. Our results confirm that anuran GRs are highly specialized nocturnal vision receptors. Moreover, their rate of phototransduction quenching appeared to be about two-times slower than in RRs, which makes them even more efficient single photon detectors. The operating intensity ranges for two rod types widely overlap supposedly allowing amphibians to discriminate colors in the scotopic region. Unexpectedly for typical cone pigments but in line with some previous reports, the spontaneous isomerization rate of the GR visual pigment was found to be the same as for rhodopsin of RRs. Thus, our results expand the knowledge on anuran GRs and show that these are even more specialized single photon catchers than RRs, which allows us to assign them a status of “super-rods”. |
format | Online Article Text |
id | pubmed-8707487 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-87074872021-12-25 Phototransduction in Anuran Green Rods: Origins of Extra-Sensitivity Astakhova, Luba A. Novoselov, Artem D. Ermolaeva, Maria E. Firsov, Michael L. Rotov, Alexander Yu. Int J Mol Sci Article Green rods (GRs) represent a unique type of photoreceptor to be found in the retinas of anuran amphibians. These cells harbor a cone-specific blue-sensitive visual pigment but exhibit morphology of the outer segment typical for classic red rods (RRs), which makes them a perspective model object for studying cone–rod transmutation. In the present study, we performed detailed electrophysiological examination of the light sensitivity, response kinetics and parameters of discrete and continuous dark noise in GRs of the two anuran species: cane toad and marsh frog. Our results confirm that anuran GRs are highly specialized nocturnal vision receptors. Moreover, their rate of phototransduction quenching appeared to be about two-times slower than in RRs, which makes them even more efficient single photon detectors. The operating intensity ranges for two rod types widely overlap supposedly allowing amphibians to discriminate colors in the scotopic region. Unexpectedly for typical cone pigments but in line with some previous reports, the spontaneous isomerization rate of the GR visual pigment was found to be the same as for rhodopsin of RRs. Thus, our results expand the knowledge on anuran GRs and show that these are even more specialized single photon catchers than RRs, which allows us to assign them a status of “super-rods”. MDPI 2021-12-13 /pmc/articles/PMC8707487/ /pubmed/34948198 http://dx.doi.org/10.3390/ijms222413400 Text en © 2021 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Astakhova, Luba A. Novoselov, Artem D. Ermolaeva, Maria E. Firsov, Michael L. Rotov, Alexander Yu. Phototransduction in Anuran Green Rods: Origins of Extra-Sensitivity |
title | Phototransduction in Anuran Green Rods: Origins of Extra-Sensitivity |
title_full | Phototransduction in Anuran Green Rods: Origins of Extra-Sensitivity |
title_fullStr | Phototransduction in Anuran Green Rods: Origins of Extra-Sensitivity |
title_full_unstemmed | Phototransduction in Anuran Green Rods: Origins of Extra-Sensitivity |
title_short | Phototransduction in Anuran Green Rods: Origins of Extra-Sensitivity |
title_sort | phototransduction in anuran green rods: origins of extra-sensitivity |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8707487/ https://www.ncbi.nlm.nih.gov/pubmed/34948198 http://dx.doi.org/10.3390/ijms222413400 |
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