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McDonald, T. L.

Publications and source records attributed to McDonald, T. L..

2 recordsLinked to original sources

The inducible lac operator-repressor system is functional in zebrafish cells

BackgroundZebrafish are a foundational model organism for studying the spatio-temporal activity of genes and their regulatory sequences. A variety of approaches are currently available for editing genes and modifying gene expression in zebrafish, including RNAi, Cre/lox, and CRISPR-Cas9. However, the lac operator-repressor system, a component of the E. coli lac operon which has been adapted for use in many other species and is a valuable, flexible tool for studying the inducible modulation of gene expression, has not previously been tested in zebrafish. ResultsHere we demonstrate that the lac operator-repressor system robustly decreases expression of firefly luciferase in cultured zebrafish fibroblast cells. Our work establishes the lac operator-repressor system as a promising tool for the manipulation of gene expression in whole zebrafish. ConclusionsOur results lay the groundwork for the development of lac-based reporter assays in zebrafish, and adds to the tools available for investigating dynamic gene expression in embryogenesis. We believe that this work will catalyze the development of new reporter assay systems to investigate uncharacterized regulatory elements and their cell-type specific activities.

molecular biology

finFindR: Computer-assisted Recognition and Identification of Bottlenose Dolphin Photos in R

O_LIPhotographic identification is an essential research and management tool for studying population size and dynamics of common bottlenose dolphins (Tursiops truncatus). Photographic identification involves recognizing individuals based on unique dorsal fin markings. Manual identification of dolphins, while successful, is labor-intensive and time-consuming. To shorten processing times, we developed a series of neural networks that finds fins, assesses their unique characteristics, and matches them to an existing catalog.\nC_LIO_LIOur software, finFindR, shortens photo-ID processing times by autonomously finding and isolating (i.e., \"cropping\") dolphin fins in raw field photographs, tracing the trailing edge of fins in cropped images, and producing a sorted list of likely identities from a catalog of known individuals. The program then presents users with the top 50 most likely matching identities, allowing users to view side-by-side image pairs and make final identity determinations.\nC_LIO_LIDuring testing on two sets of novel images, finFindR placed the correct individual in the first position of its ordered list in 88% (238/272 and 354/400) of test cases. finFindR placed the correct identity among the top 10 ranked images in 94% of test cases, and among the top 50 ranked images in 97% of test cases. Hence, if a match does not exist in the first 50 images of finFindRs ordered list, researchers can be almost certain (~97%) that a match does not exist in the entire catalog.\nC_LIO_LIDuring a head-to-head blind test of the human-only and finFindR-assisted matching methods, two experienced photo-ID technicians both achieved 97% correct identification of identities when matched against a catalog containing over 2,000 known individuals. However, the manual-only technician examined 124 images on average before making a match, while the technician using finFindR examined only 10 images on average before finding a match.\nC_LIO_LIWe conclude that finFindR will facilitate equal or improved match accuracy while greatly reducing the number of examined photos. The faster matches, automated detection, and automated cropping afforded by finFindR will greatly reduce typical photo-ID processing times.\nC_LI

bioinformatics