| 1. |
- Cechetto, Clément, et al.
(author)
-
Retinal Ganglion Cell Topography and Spatial Resolving Power in Echolocating and Non-Echolocating Bats
- 2020
-
In: Brain, Behavior and Evolution. - : S. Karger AG. - 0006-8977 .- 1421-9743. ; 95:2, s. 58-68
-
Journal article (peer-reviewed)abstract
- Bats are nocturnal mammals known for their ability to echolocate, yet all bats can see, and most bats of the family Pteropodidae (fruit bats) do not echolocate-instead they rely mainly on vision and olfaction to forage. We investigated whether echolocating bats, given their limited reliance on vision, have poorer spatial resolving power (SRP) than pteropodids and whether tongue click echolocating fruit bats differ from non-echolocating fruit bats in terms of visual performance. We compared the number and distribution of retinal ganglion cells (RGCs) as well as the maximum anatomical SRP derived from these distributions in 4 species of bats: Myotis daubentonii, a laryngeal echolocating bat from the family Vespertilionidae, Rousettus aegyptiacus, a tongue clicking echolocating bat from the family Pteropodidae, and Pteropus alecto and P. poliocephalus, 2 non-echolocating bats (also from the Pteropodidae). We find that all 3 pteropodids have a similar number (≈200,000 cells) and distribution of RGCs and a similar maximum SRP (≈4 cycles/degree). M. daubentonii has fewer (∼6,000 cells) and sparser RGCs than the pteropodids and thus a significantly lower SRP (0.6 cycles/degree). M. daubentonii also differs in terms of the distribution of RGCs by having a unique dorsal area of specialization in the retina. Our findings are consistent with the existing literature and suggest that M. daubentonii likely only uses vision for orientation, while for pteropodids vision is also important for foraging.
|
|
| 2. |
- Musilova, Zuzana, et al.
(author)
-
Vision using multiple distinct rod opsins in deep-sea fishes
- 2019
-
In: Science. - Washington : American Association of Advanced Science. - 0036-8075 .- 1095-9203. ; 364:6440, s. 588-
-
Journal article (peer-reviewed)abstract
- Vertebrate vision is accomplished through light-sensitive photopigments consisting of an opsin protein bound to a chromophore. In dim light, vertebrates generally rely on a single rod opsin [rhodopsin 1 (RH1)] for obtaining visual information. By inspecting 101 fish genomes, we found that three deep-sea teleost lineages have independently expanded their RH1 gene repertoires. Among these, the silver spinyfin (Diretmus argenteus) stands out as having the highest number of visual opsins in vertebrates (two cone opsins and 38 rod opsins). Spinyfins express up to 14 RH1s (including the most blueshifted rod photopigments known), which cover the range of the residual daylight as well as the bioluminescence spectrum present in the deep sea. Our findings present molecular and functional evidence for the recurrent evolution of multiple rod opsin-based vision in vertebrates.
|
|
