Biology subjects

Groves, I.

Publications and source records attributed to Groves, I..

3 recordsLinked to original sources

bioRxiv2022

A neuroepithelial wave of BMP signalling drives anteroposterior specification of the tuberal hypothalamus

The tuberal hypothalamus houses several major hypothalamic nuclei, dozens of transcriptionally distinct cell types, and clinically relevant cell populations implicated in obesity and related metabolic disorders. Building on recent advances in the field, here we draw upon transcriptional, signalling, and fate mapping analyses of chicken embryos and neuroepithelial explants to analyze tuberal hypothalamic development. We show that a wave of BMP signalling sweeps through early floor plate-like progenitors overlying prospective Rathkes pouch as they track anteriorly. The timing of BMP signalling correlates with cell fate, with anterior tuberal specification complete by Hamilton-Hamburger (HH) stage 10 but posterior tuberal progenitors requiring BMPs after this point. scRNA-Seq profiling of FGF10-expressing cells, a proxy for cells with active BMP signalling, through HH8-21 reveals transcriptional differences that may underlie their differing response to BMPs, and the switch from neuroepithelial progenitors to stem-like radial glial cells. This study provides an integrated account of the development of the tuberal hypothalamus.

developmental biology↗

bioRxiv2022

Bespoke data augmentation and network construction enable image classification on small microscopy datasets

Recent work has indicated a need for increased temporal resolution for studies of the early chick brain. Over a 10-hour period, the developmental potential of progenitor cells in the HH10 brain changes, and concomitantly, the brain undergoes subtle changes in morphology. We asked if we could train a deep convolutional neural network to sub-stage HH10 brains from a small dataset (<200 images). By augmenting our images with a combination of biologically informed transformations and data-driven preprocessing steps, we successfully trained a classifier to sub-stage HH10 brains to 87.1% test accuracy. To determine whether our classifier could be generally applied, we re-trained it using images (<250) of randomised control and experimental chick wings, and obtained similarly high test accuracy (86.1%). Saliency analyses revealed that biologically relevant features are used for classification. Our strategy enables training of image classifiers for various applications in developmental biology with limited microscopy data. SUMMARY STATEMENTWe train a deep convolutional network that can be generally applied to accurately classify chick embryos from images. Saliency analyses show that classification is based on biologically relevant features.

developmental biology↗

bioRxiv2021

Impact of carbon monoxide on early cardiac development in an avian model

Carbon monoxide (CO) is a toxic gas that can be lethal in large doses and may also cause physiological damage in lower doses. Epidemiological studies suggest that CO in lower doses over time may impact on embryo development, in particular cardiac development, however other studies have not observed this association. Here, we exposed chick embryos in ovo to CO at three different concentrations (1ppm, 8ppm, 25ppm) plus air control (4 protocols in total) for the first nine days of development, at which point we assessed egg and embryo weight, ankle length, developmental stage, heart weight and ventricular wall thickness. We found that heart weight was reduced for the low and moderate exposures compared to air, and that ventricular wall thickness was increased for the moderate and high exposures compared to air. Ventricular wall thickness was also significantly positively correlated with absolute CO exposures across all protocols. This intervention study thus suggests that CO even at very low levels may have a significant impact on cardiac development.

developmental biology↗