Biology subjects

Orth, A.

Publications and source records attributed to Orth, A..

3 recordsLinked to original sources

bioRxiv2023

Phenogenomic resources immortalized in a panel of wild-derived strains of five species of house mice

The house mouse, Mus musculus, is a widely used animal model in biomedical research, with classical laboratory strains (CLS) being the most frequently employed. However, the limited genetic variability in CLS hinders their applicability in evolutionary studies. Wild-derived strains (WDS), on the other hand, provide a suitable resource for such investigations. This study quantifies genetic and phenotypic data of 101 WDS representing 5 species, 3 subspecies, and 8 natural Y consomic strains and compares them with CLS. Genetic variability was estimated using whole mtDNA sequences, the Prdm9 gene, and copy number variation at two sex chromosome-linked genes. WDS exhibit a large natural variation with up to 2173 polymorphic sites in mitogenomes, whereas CLS display 92 sites. Moreover, while CLS have two Prdm9 alleles, WDS harbour 46 different alleles. Although CLS resemble M. m. domesticus and M. m. musculus WDS, they differ from them in 8 and 11 out of 15 phenotypic traits, respectively. The results suggest that WDS can be a useful tool in evolutionary studies and have great potential for medical applications.

evolutionary biology↗

bioRxiv2018

Super-multiplexed fluorescence microscopy via photostability contrast

Many areas of biological research rely heavily on fluorescence microscopy to observe and quantify the inner workings of the cell. Traditionally, multiple types of cellular structures or biomolecules are visualized simultaneously with spectrally distinct fluorescent labels. A high degree of multiplexing is desirable as it affords the experiment greater information content, speeding up research timelines. Multiplexing can be increased by imaging a larger number of spectral channels, however, the wide emission spectra of most fluorophores limits multiplexing to four or five labels in standard fluorescence microscopes. Further multiplexing requires another dimension of contrast. Here, we show that photostability differences can be used to distinguish between fluorescent labels. By combining photobleaching characteristics with a novel unmixing algorithm, we resolve up to three fluorescent labels in a single spectral channel and unmix fluorescent labels with nearly identical emission spectra. We apply our technique to organic dyes, autofluorescent biomolecules and fluorescent proteins, and show that the latter are particularly well suited to our method as their bleaching is often reversible. Our approach has the potential to triple the multiplexing capabilities of any digital widefield or confocal fluorescence microscope with no additional hardware, making it readily accessible to a wide range of researchers.

bioengineering↗

bioRxiv2017

A dual-mode mobile phone microscope using integrated and ambient light

Mobile phone microscopes are a natural platform for point-of-care imaging, but current solutions require an externally powered illumination source, thereby adding bulk and cost. We present a mobile phone microscope that uses the internal flash or sunlight as the illumination source, thereby reducing complexity whilst maintaining functionality and performance. The microscope is capable of both brightfield and darkfield imaging modes, enabling microscopic visualization of samples ranging from plant to mammalian cells. We describe the microscope design principles, assembly process, and demonstrate its imaging capabilities through the visualization of unlabelled cell nuclei to observing the motility of cattle sperm.

bioengineering↗