Dataset Information

Three spectrally distinct photoreceptors in diurnal and nocturnal Australian ants.

ABSTRACT: Ants are thought to be special among Hymenopterans in having only dichromatic colour vision based on two spectrally distinct photoreceptors. Many ants are highly visual animals, however, and use vision extensively for navigation. We show here that two congeneric day- and night-active Australian ants have three spectrally distinct photoreceptor types, potentially supporting trichromatic colour vision. Electroretinogram recordings show the presence of three spectral sensitivities with peaks (?max) at 370, 450 and 550 nm in the night-active Myrmecia vindex and peaks at 370, 470 and 510 nm in the day-active Myrmecia croslandi. Intracellular electrophysiology on individual photoreceptors confirmed that the night-active M. vindex has three spectral sensitivities with peaks (?max) at 370, 430 and 550 nm. A large number of the intracellular recordings in the night-active M. vindex show unusually broad-band spectral sensitivities, suggesting that photoreceptors may be coupled. Spectral measurements at different temporal frequencies revealed that the ultraviolet receptors are comparatively slow. We discuss the adaptive significance and the probability of trichromacy in Myrmecia ants in the context of dim light vision and visual navigation.

SUBMITTER: Ogawa Y

PROVIDER: S-EPMC4455814 | biostudies-other | 2015 Jun

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Three spectrally distinct photoreceptors in diurnal and nocturnal Australian ants.

Ogawa Yuri Y Falkowski Marcin M Narendra Ajay A Zeil Jochen J Hemmi Jan M JM

Proceedings. Biological sciences 20150601 1808

Ants are thought to be special among Hymenopterans in having only dichromatic colour vision based on two spectrally distinct photoreceptors. Many ants are highly visual animals, however, and use vision extensively for navigation. We show here that two congeneric day- and night-active Australian ants have three spectrally distinct photoreceptor types, potentially supporting trichromatic colour vision. Electroretinogram recordings show the presence of three spectral sensitivities with peaks (λmax) ...[more]

PMID: 25994678

Similar Datasets

Project description:BackgroundA number of non-visual responses to light in vertebrates, such as circadian rhythm control and pupillary light reflex, are mediated by melanopsins, G-protein coupled membrane receptors, conjugated to a retinal chromophore. In non-mammalian vertebrates, melanopsin expression is variable within the retina and extra-ocular tissues. Two paralog melanopsin genes were classified in vertebrates, Opn4x and Opn4m. Snakes are highly diversified vertebrates with a wide range of daily activity patterns, which raises questions about differences in structure, function and expression pattern of their melanopsin genes. In this study, we analyzed the melanopsin genes expressed in the retinas of 18 snake species from three families (Viperidae, Elapidae, and Colubridae), and also investigated extra-retinal tissue expression.ResultsPhylogenetic analysis revealed that the amplified gene belongs to the Opn4x group, and no expression of the Opn4m was found. The same paralog is expressed in the iris, but no extra-ocular expression was detected. Molecular evolutionary analysis indicated that melanopsins are evolving primarily under strong purifying selection, although lower evolutionary constraint was detected in snake lineages (ω = 0.2), compared to non-snake Opn4x and Opn4m (ω = 0.1). Statistical analysis of selective constraint suggests that snake phylogenetic relationships have driven stronger effects on melanopsin evolution, than the species activity pattern. In situ hybridization revealed the presence of melanopsin within cells in the outer and inner nuclear layers, in the ganglion cell layer, and intense labeling in the optic nerve.ConclusionsThe loss of the Opn4m gene and extra-ocular photosensitive tissues in snakes may be associated with a prolonged nocturnal/mesopic bottleneck in the early history of snake evolution. The presence of melanopsin-containing cells in all retinal nuclear layers indicates a globally photosensitive retina, and the expression in classic photoreceptor cells suggest a regionalized co-expression of melanopsin and visual opsins.

Dataset Information

Three spectrally distinct photoreceptors in diurnal and nocturnal Australian ants.

Publications

Three spectrally distinct photoreceptors in diurnal and nocturnal Australian ants.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets