Biology subjects

Rohde, L.

Publications and source records attributed to Rohde, L..

3 recordsLinked to original sources

bioRxiv2024

Unified Mass Imaging Maps the Lipidome of Vertebrate Development

Embryo development entails the formation of anatomical structures with distinct biochemical compositions. Compared with the wealth of knowledge on gene regulation, our understanding of metabolic programs operating during embryogenesis is limited. Mass spectrometry imaging (MSI) has the potential to map the distribution of metabolites across embryo development. Here, we established an analytical framework for the joint analysis of large MSI datasets that allows for the construction of multi-dimensional metabolomic atlases. Employing this framework, we mapped the 4D distribution of over a hundred lipids at quasi-single-cell resolution in Danio rerio embryos. We discovered metabolic trajectories that unfold in concert with morphogenesis and revealed spatially organized biochemical coordination overlooked by bulk measurements. Interestingly, lipid mapping revealed unexpected distributions of sphingolipid and triglyceride species, suggesting their involvement in pattern establishment and organ development. Our approach empowers a new generation of whole-organism metabolomic atlases and enables the discovery of spatially organized metabolic circuits.

systems biology↗

bioRxiv2023

But, what are the cells doing? Image Analysis pipeline to follow single cells in the zebrafish embryo

Microscopy has rapidly evolved at pace with live markers, enabling ever higher spatiotemporal resolution of multicellular dynamics within larger fields of view. Consequently, we are now in the era of widespread production of terabyte (TB)-sized time-lapse movies of experimental model systems, including developing embryos and organoids. Working with these large datasets has presented a new set of hurdles, particularly due to the lack of standardized open-source pipelines for acquiring, handling and analyzing the data. Moreover, although long-term tracking of a cell throughout an entire process, for example vertebrate organogenesis, is key to revealing the underlying cellular dynamics, this has proven largely elusive. To specifically address the question "But, what are the cells doing?", we created an image analysis pipeline optimized to track single cells in light-sheet acquired datasets (1 TB sized time-lapse, 8h of imaging, 30 min gene expression cycle, cell movement speed (1{micro}m /1 minute), 200-400 {micro}m tissue depth). Our modular pipeline optimizes and connects the following: image acquisition parameters to improve tracking feasibility; hardware specifications; data handling and compression tools; pre-processing steps; state-of-the-art cell tracking tools (Mastodon, MaMuT) and a novel open-source/ python-based tool (Paleontologist) to analyze and visualize spatiotemporal dynamics of the tracked cells. Importantly, our pipeline is adaptable to a variety of experimental systems and accessible to researchers regardless of expertise in coding and image analysis. One-sentence SummaryUser-friendly cell-tracking pipeline that connects image acquisition in multicellular systems through to data analysis of cellular dynamics.

developmental biology↗

bioRxiv2020

Theory of genetic oscillations with external noisy regulation

We present a general theory of noisy genetic oscillators with externally regulated production rate. The observables that characterize the genetic oscillator are discussed, and it is shown how their statistics depend on the statistics of the external regulator. We show that these observables have generic features that are observed in two different experimental systems: the expression of the circadian clock genes in fibroblasts, and in the transient and oscillatory dynamics of the segmentation clock genes observed in cells disassociated from zebrafish embryos. Our work shows that genetic oscillations with diverse biological contexts can be understood in a common framework based on delayed negative feedback system, and slow regulator dynamics.

biophysics↗