The effect of discrete wavelengths of visible light on the developing murine embryo

Open Access funding enabled and organized by CAUL and its Member Institutions KRD is supported by a Mid-Career Fellowship from the Hospital Research Foundation (C-MCF-58–2019). KD is supported by funding from the UK Engineering and Physical Sciences Research Council (EP/P030017/1) and the Australian Research Council (FL210100099). CC acknowledges the support of a PhD scholarship jointly from the University of Adelaide and University of Nottingham. This study was funded by the Australian Research Council Centre of Excellence for Nanoscale BioPhotonics (CE140100003). PR acknowledges funding through the RMIT Vice-Chancellor’s Research Fellowship and ARC DECRA Fellowship scheme (DE200100279).Purpose A current focus of the IVF field is non-invasive imaging of the embryo to quantify developmental potential. Such approaches use varying wavelengths to gain maximum biological information. The impact of irradiating the developing embryo with discrete wavelengths of light is not fully understood. Here, we assess the impact of a range of wavelengths on the developing embryo. Methods Murine preimplantation embryos were exposed daily to wavelengths within the blue, green, yellow, and red spectral bands and compared to an unexposed control group. Development to blastocyst, DNA damage, and cell number/allocation to blastocyst cell lineages were assessed. For the longer wavelengths (yellow and red), pregnancy/fetal outcomes and the abundance of intracellular lipid were investigated. Results Significantly fewer embryos developed to the blastocyst stage when exposed to the yellow wavelength. Elevated DNA damage was observed within embryos exposed to blue, green, or red wavelengths. There was no effect on blastocyst cell number/lineage allocation for all wavelengths except red, where there was a significant decrease in total cell number. Pregnancy rate was significantly reduced when embryos were irradiated with the red wavelength. Weight at weaning was significantly higher when embryos were exposed to yellow or red wavelengths. Lipid abundance was significantly elevated following exposure to the yellow wavelength. Conclusion Our results demonstrate that the impact of light is wavelength-specific, with longer wavelengths also impacting the embryo. We also show that effects are energy-dependent. This data shows that damage is multifaceted and developmental rate alone may not fully reflect the impact of light exposure.Publisher PDFPeer reviewe

Development of Bright and Biocompatible Nanoruby and Its Application to Background-Free Time-Gated Imaging of G‑Protein-Coupled Receptors

At the forefront of developing fluorescent probes for biological imaging applications are enhancements aimed at increasing their brightness, contrast, and photostability, especially toward demanding applications of single-molecule detection. In comparison with existing probes, nanorubies exhibit unlimited photostability and a long emission lifetime (∼4 ms), which enable continuous imaging at single-particle sensitivity in highly scattering and fluorescent biological specimens. However, their wide application as fluorescence probes has so far been hindered by the absence of facile methods for scaled-up high-volume production and molecularly specific targeting. The present work encompasses the large-scale production of colloidally stable nanoruby particles, the demonstration of their biofunctionality and negligible cytotoxicity, as well as the validation of its use for targeted biomolecular imaging. In addition, optical characteristics of nanorubies are found to be comparable or superior to those of state-of-the-art quantum dots. Protocols of reproducible and robust coupling of functional proteins to the nanoruby surface are also presented. As an example, NeutrAvidin-coupled nanoruby show excellent affinity and specificity to μ-opioid receptors in fixed and live cells, allowing wide-field imaging of G-protein coupled receptors with single-particle sensitivity