Publication: Photoreceptor fine structure in the bobtail goanna
(Tiliqua rugosa)
Loading...
Date
1989
Authors
Braekevelt, Charlie R.
item.page.secondaryauthor
item.page.director
Publisher
Murcia : F. Hernández
publication.page.editor
publication.page.department
DOI
item.page.type
info:eu-repo/semantics/article
Description
The fine structure of the retinal photoreceptors
has been studied by light and electron microscopy in
the bobtail goanna (Tiliqua rugosa) an Australian diurna1
lizard. The photoreceptors in this species are readily
divisible into rods or cones based on morphological
criteria. Single cones are the dominate cell type with a
cone:rod ratio of about 80: 1. No multiple photoreceptors
were present nor was a photoreceptor mosiac observed.
Cones are large cells with a short, tapering outer
segment. The inner segment contains a large apical oil
droplet, an ellipsoid of mitochondria and a prominent
paraboloid of glycogen. Rods are slender cells with a
longer ncn-tapeiing outer segment. Rod inner segnlents
display an ellipsoid but no oil droplet or paraboloid. The
nuclei of cones are large and vesicular while rod nuclei
are smaller and displayed more heterochromatin. The
synaptic pedicle of cones is larger than the spherule of
rods. Both rods and cones displayed both invaginated
(ribbor?) and conventional synapses with the large cones
having more synaptic sites. As only light-adapted
specirnens were examined it is uilcertain if either rods or
cones are capable of retinomotor responses.
Abstract
The fine structure of the retinal photoreceptors
has been studied by light and electron microscopy in
the bobtail goanna (Tiliqua rugosa) an Australian diurna1
lizard. The photoreceptors in this species are readily
divisible into rods or cones based on morphological
criteria. Single cones are the dominate cell type with a
cone:rod ratio of about 80: 1. No multiple photoreceptors
were present nor was a photoreceptor mosiac observed.
Cones are large cells with a short, tapering outer
segment. The inner segment contains a large apical oil
droplet, an ellipsoid of mitochondria and a prominent
paraboloid of glycogen. Rods are slender cells with a
longer ncn-tapeiing outer segment. Rod inner segnlents
display an ellipsoid but no oil droplet or paraboloid. The
nuclei of cones are large and vesicular while rod nuclei
are smaller and displayed more heterochromatin. The
synaptic pedicle of cones is larger than the spherule of
rods. Both rods and cones displayed both invaginated
(ribbor?) and conventional synapses with the large cones
having more synaptic sites. As only light-adapted
specirnens were examined it is uilcertain if either rods or
cones are capable of retinomotor responses.
publication.page.subject
Citation
item.page.embargo
Ir a Estadísticas
Sin licencia Creative Commons.