Simplified homology-assisted CRISPR for gene editing in Drosophila.

In vivo genome editing with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 generates powerful tools to study gene regulation and function. We revised the homology-assisted CRISPR knock-in method to convert Drosophila GAL4 lines to LexA lines using a new universal knock-in donor strain. A balancer chromosome-linked donor strain with both body color (yellow) and eye red fluorescent protein (RFP) expression markers simplified the identification of LexA knock-in using light or fluorescence microscopy. A second balancer chromosome-linked donor strain readily converted the second chromosome-linked GAL4 lines regardless of target location in the cis-chromosome but showed limited success for the third chromosome-linked GAL4 lines. We observed a consistent and robust expression of the yellow transgene in progeny harboring a LexA knock-in at diverse genomic locations. Unexpectedly, the expression of the 3xP3-RFP transgene in the "dual transgene" cassette was significantly increased compared with that of the original single 3xP3-RFP transgene cassette in all tested genomic locations. Using this improved screening approach, we generated 16 novel LexA lines; tissue expression by the derived LexA and originating GAL4 lines was similar or indistinguishable. In collaboration with 2 secondary school classes, we also established a systematic workflow to generate a collection of LexA lines from frequently used GAL4 lines.

The use of optical coherence tomography to aid in diagnosing solar maculopathy.

BACKGROUND: Solar maculopathy is most commonly diagnosed after the direct viewing of solar eclipses. The damage to the retina is located in the outer segments of photoreceptors and in the retinal pigmentary epithelium. It may be acceptable to use optical coherence tomography (OCT) to identify retinal damage caused by the sun. CASE REPORT: Here we describe a case of a patient who reported with a mild decrease in best-corrected visual acuities. Dilated examination found macular changes that were present in both eyes resembling solar maculopathy. OCT was utilized to aid in the diagnosis of solar maculopathy. CONCLUSIONS: With the large number of individuals who spend their time in the sun, a practitioner should consider the possible repercussions of this activity. We are all aware of the damage that the sun can cause to the skin and, as in the case of cataracts, its effects on the eye. In cases in which macular changes are noted we should consider the possibility of solar maculopathy. As is in the case presented here, OCT may be an effective means of assessing the maculopathy.