Calcium Homeostasis in Fly Photoreceptor Cells

2002 ◽  
pp. 539-583 ◽  
Author(s):  
Johannes Oberwinkler
Keyword(s):  
Calcium Homeostasis ◽  
Photoreceptor Cells ◽  
Fly Photoreceptor

scholarly journals Calcium Transients in the Rhabdomeres of Dark- and Light-Adapted Fly Photoreceptor Cells

2000 ◽  
Vol 20 (5) ◽  
pp. 1701-1709 ◽  
Author(s):  
Johannes Oberwinkler ◽  
Doekele G. Stavenga
Keyword(s):  
Photoreceptor Cells ◽  
Calcium Transients ◽  
Fly Photoreceptor

Spindle shaped bodies in foveolar cones of the baboon retina

1989 ◽  
Vol 47 ◽  
pp. 960-961
Author(s):  
W. Krebs ◽  
I. Krebs
Keyword(s):  
Cross Sections ◽  
Inclusion Bodies ◽  
Photoreceptor Cells ◽  
Papio Anubis ◽  
Retinal Photoreceptor ◽  
Age Related ◽  
Cone Cells ◽  
Membrane Bound ◽  
Oriented Parallel ◽  
Shaped Inclusion

Various inclusion bodies occur in vertebrate retinal photoreceptor cells. Most of them are membrane bound and associated with phagocytosis or they are age related residual bodies. We found an additional inclusion body in foveal cone cells of the baboon (Papio anubis) retina.The eyes of a 15 year old baboon were fixed by immersion in cacodylate buffered glutaraldehyde (2%)/formaldehyde (2%) as described in detail elsewhere . Pieces of retina from various locations, including the fovea, were embedded in epoxy resin such that radial or tangential sections could be cut.Spindle shaped inclusion bodies were found in the cytoplasm of only foveal cones. They were abundant in the inner segments, close to the external limiting membrane (Fig. 1). But they also occurred in the outer fibers, the perikarya, and the inner fibers (Henle’s fibers) of the cone cells. The bodies were between 0.5 and 2 μm long. Their central diameter was 0.2 to 0. 3 μm. They always were oriented parallel to the long axis of the cone cells. In longitudinal sections (Figs. 2,3) they seemed to have a fibrous skeleton that, in cross sections, turned out to consist of plate-like (Fig.4) and tubular profiles (Fig. 5).

Differentiation Processes of the Ocellar Retina of the Honeybee (Apis Mellifera L.)

1990 ◽  
Vol 48 (3) ◽  
pp. 430-431
Author(s):  
Maria Anna Pabst
Keyword(s):  
Apis Mellifera ◽  
Distal Part ◽  
Cell Layer ◽  
Single Layer ◽  
Photoreceptor Cells ◽  
Distal Segment ◽  
Compound Eyes ◽  
Thin Sections ◽  
Ultrastructural Studies ◽  
Adult Worker

In addition to the compound eyes, honeybees have three dorsal ocelli on the vertex of the head. Each ocellus has about 800 elongated photoreceptor cells. They are paired and the distal segment of each pair bears densely packed microvilli forming together a platelike fused rhabdom. Beneath a common cuticular lens a single layer of corneagenous cells is present.Ultrastructural studies were made of the retina of praepupae, different pupal stages and adult worker bees by thin sections and freeze-etch preparations. In praepupae the ocellar anlage consists of a conical group of epidermal cells that differentiate to photoreceptor cells, glial cells and corneagenous cells. Some photoreceptor cells are already paired and show disarrayed microvilli with circularly ordered filaments inside. In ocelli of 2-day-old pupae, when a retinogenous and a lentinogenous cell layer can be clearly distinguished, cell membranes of the distal part of two photoreceptor cells begin to interdigitate with each other and so start to form the definitive microvilli. At the beginning the microvilli often occupy the whole width of the developing rhabdom (Fig. 1).

Actin and α-tubulin immuno-EM labelings reveal differences in intra versus interphotoreceptor matrix

1990 ◽  
Vol 48 (3) ◽  
pp. 466-467
Author(s):  
Matti Järvilehto ◽  
Riitta Harjula
Keyword(s):  
Compound Eye ◽  
Frozen Section ◽  
Smooth Muscle Actin ◽  
Photoreceptor Cells ◽  
Immune Serum ◽  
Cell Organelles ◽  
Calliphora Erythrocephala ◽  
Optical Axes ◽  
Interphotoreceptor Matrix ◽  
Similar Kind

The photoreceptor cells in the compound eyes of higher diptera are clustered in groups (ommatidia) of eight receptor cells. The cells from six adjacent ommatidia are organized into optical units, neuro-ommatia sharing the same visual field. In those ommatidia the optical axes of the photopigment containing structures (rhabdomeres) are parallel. The rhabdomeres of the photoreceptor cells are separated from each other by an interstitial i.e innerommatidial space (IOS). In the photoreceptor cell body, besides of the normal cell organelles, a cellular matrix is a structurally apparent component. Similar kind of reticular formation is also found in the IOS containing some unidentified filamentary substance, of which composition and functional significance for optical properties of vision is the aim of this report.The prefixed (2% PA + 0.2% GA in 0.1-n phosphate buffer, pH 7.4, for 1h), frozen section blocks of the compound eye of the blowfly (Calliphora erythrocephala) were prepared by immuno-cryo-techniques. The ultrathin cryosections were incubated with antibodies of monoclonal α-tubulin and polyclonal smooth muscle actin. Control labelings of excess of antigen, non-immune serum and non-present antibody were perforated.

Calcium homeostasis in gallbladder epithelium is altered during earty galistone formation

2001 ◽  
Vol 120 (5) ◽  
pp. A386-A386
Author(s):  
S NARINS ◽  
J DOUGHERTY ◽  
E PARK ◽  
R NICHOLS ◽  
P SMITH ◽  
...  
Keyword(s):  
Calcium Homeostasis ◽  
Gallbladder Epithelium
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