# A method for analysing tissue motion and deformation during mammalian organogenesis

## TL;DR

This paper introduces a computational method to combine fragmented live imaging data of mouse heart development into a continuous model, revealing how tissues deform and cells move during organ formation.

## Contribution

A novel computational framework that integrates fragmented live imaging data into a dynamic consensus model of mammalian heart development.

## Key findings

- The method enables quantification of tissue growth and anisotropy during heart development.
- An in-silico fate map of cardiomyocyte trajectories was generated from the integrated model.
- The approach overcomes limitations of traditional live imaging by combining multiple partial observations.

## Abstract

Understanding tissue morphogenesis is an important goal in developmental biology and tissue engineering. Accurately describing tissue deformation processes and how cell rearrangements contribute to these is a challenging task. Live analysis of morphogenesis in 3D is frequently used to obtain source data that allow to extract such features from developing organs. However, several limitations are encountered when applying these methodologies to mammalian embryos. The mouse embryo is the most frequently used model, but most studies use a very limited number of specimens and present only individual acquisitions due to constraints imposed by embryo culture and imaging. Here, we leverage live imaging of mouse heart development to build a novel computational framework that overcomes these limitations. Our methodology first extracts tissue dynamics from individual specimens and then integrates these fragmented datasets into a deterministic and dynamic consensus model of heart development. This integrated model allows us to quantify patterns of tissue growth and anisotropy and generate an in-silico fate map of cardiomyocyte trajectories. This work provides a foundational toolkit for dissecting the complex morphogenetic processes underlying mammalian organogenesis, converting collections of variable live images into robust, quantitative blueprints of development.

How can a small cluster of cells become a beating heart? This is a fascinating question, and one that science has not yet fully answered. Observing this process in real time is challenging: capturing video during embryonic development requires dedicated techniques and many hours at the microscope. Often, researchers only obtain brief observation windows, too limited to cover the entire process. In practice, we usually end up with just scattered fragments of a much longer story.

In our work, we found a way to turn these fragments into a continuous narrative. Using live imaging of mouse embryos and computational tools, we were able to combine many partial observations into a single dynamic model of how the heart forms. It's a bit like creating a time-lapse: we can watch the tissue grow, the shape of the organ change, and even follow the paths of the cells that build it.

By bringing these segments together into a coherent blueprint, we offer a new perspective on how nature brings the heart to life. Beyond revealing part of this developmental mystery, our approach also opens new avenues for understanding how other complex organs form.