Gallery of Images:


These are some of our favorite images from our research. X. laevis photoreceptors are particularly amenable to analysis by confocal microscopy due to their relatively large size. All images copyright Orson L. Moritz. Check back soon for updates!

Transgenic photoreceptors expressing a mislocalizing rhodopsin mutant. Unlike normal rhodopsin, the mutant rhodopsin is present in the inner segment plasma membrane (unusual) in addition to the rod outer segment (normal). These cells have also developed abnormal processes that extend horizontally through the outer nuclear layer, and vertically through the inner nuclear layer to the ganglion cell layer. Similar effects may occur in the retinas of RP patients. For more info, see our 2006 publication in J Neuroscience.


Transgenic photoreceptors expressing the P23H rhodopsin mutant. This is the most common RP-causing rhodopsin mutation in North America. Unlike normal rhodopsin, the mutant protein (stained green) is primarily found in the inner segment, the site of rhodopsin synthesis. The red stain indicates a protein called calnexin, which is present in the endoplasmic reticulum, and the combination of red and green stains make yellow. Normal rhodopsin is rapidly removed from the site of synthesis in the endoplasmic reticulum and transported to the rod outer segment, where only a few thin bands of P23H rhodopsin are apparent in this retina. This suggests that there is a problem with the synthesis or transport of the P23H protein. Usually, retention in the endoplasmic reticulum indicates a defect in protein folding. Similar effects may occur in the retinas of RP patients carrying this mutation. For more info, see an additional gallery of images relevant to P23H rhodopsin, as well as our 2006 publication in IOVS.

Transgenic photoreceptors expressing bovine P23H rhodopsin, demonstrating differential reactivity of N- and C-terminal antibody epitopes. While the C-terminus (1D4) is abundant in the outer segments, the N-terminal epitope (2B2) is largely absent from the outer segments, and relatively speaking, is much more abundant in inner segments. This is due to the fact that the N-terminus of P23H rhodopsin is cleaved on exit from the ER. For more info, click here, or see our 2007 publication in J Neuroscience.

xenopus oct

X. laevis retina imaged using optical coherence tomography (OCT). We can use this technique (right panels, DIC/fluorescence microscopy on left) to diagnose retinal degeneration in living tadpoles. For more info, see our 2009 paper in IOVS. These images were obtained as part of a collaboration with Dr. Marinko Sarunic.

Transgenic cone photoreceptors expressing jellyfish green fluorescent protein (GFP). This experiment demonstrates that we can genetically manipulate X. laevis cone photoreceptors to express proteins that we wish to study. Here, we have expressed a fluorescent green protein from jellyfish, which is easy to detect with a microscope (the green signal). However, we can use the same technique to express proteins that cause genetic disorders, or prevent cone cell death. In this image, the rod outer segments have been counterstained red. This image also demonstrates the high cone:rod ratio of the X. laevis retina (aproximately 1:1). For more info, see our 2002 publication in Gene.



We've also linked to pictures from lab and department outings and conferences, including:


We've added separate galleries containing additional images relevant to recent findings, including:

 P23H rhodopsin