Highly-restricted, cell-specific expression of the simian CMV-IE promoter in transgenic zebrafish with age and after heat shock.

Promoters with high levels of ubiquitous expression are of significant utility in the production of transgenic animals and cell lines. One such promoter is derived from the human cytomegalovirus immediate early (CMV-IE) gene. We sought to ascertain if the simian CMV-IE promoter (sCMV), used extensively in non-mammalian vertebrate research, also directs intense, widespread expression when stably introduced into zebrafish.

Mitral cells in the olfactory bulb of adult zebrafish (Danio rerio): morphology and distribution.

The mitral cell is the primary output neuron and central relay in the olfactory bulb of vertebrates. The morphology of these cells has been studied extensively in mammalian systems and to a lesser degree in teleosts. This study uses retrograde tract tracing and other techniques to characterize the morphology and distribution of mitral cells in the olfactory bulb of adult zebrafish, Danio rerio.

Changes in glutamate receptor subunit 4 expression in the deafferented olfactory bulb of zebrafish.

The distribution of ionotropic glutamate receptor subunit 4 (iGluR4) was examined in both normal and deafferented olfactory bulbs of adult zebrafish, Danio rerio. With the exception of the olfactory nerve layer, there was extensive labeling with antibodies to iGluR4 in the olfactory bulbs, specifically in juxtaglomerular cell bodies and their processes. These results are consistent with previous work, which has suggested differential distribution of glutamate receptors in the vertebrate olfactory system.

Ruffed cells identified in the adult zebrafish olfactory bulb.

The morphology and distribution of ruffed cells was examined in the olfactory bulb of adult zebrafish, Danio rerio, using retrograde tract tracing and Golgi-Kopsch techniques. The neurons had variable-shaped soma that ranged in size from 7 to 15 microm in diameter. There was an obvious protrusion of the membrane, a ruff, near the initial portion of the axon, and the cells appeared to be distributed primarily in the glomerular layer and superficial internal cell layer.

Apoptosis following peripheral sensory deafferentation in the olfactory bulb of adult zebrafish.

Removal of the olfactory organ in adult zebrafish results in a significant decrease in volume of the ipsilateral olfactory bulb. The current study investigated the potential role of apoptosis in this phenomenon. It was hypothesized that cells in the adult olfactory bulb normally undergo minimal apoptosis and that apoptosis increases upon removal of sensory stimulation.