# Spatiotemporal segmentation of contraction waves in the extra-embryonic membranes of the red flour beetle

## TL;DR

This paper introduces a new image analysis method to study contraction waves in the red flour beetle's embryonic membranes, revealing novel patterns during development.

## Contribution

A novel image analysis pipeline for spatiotemporal segmentation and quantification of contraction waves in 2D+t and 3D+t microscopy data.

## Key findings

- The pipeline reliably detects contraction waves in Tribolium embryonic membranes using light-sheet fluorescence microscopy.
- Quantitative metrics such as wave duration, frequency, and spatial distribution are extracted automatically.
- The method is adaptable for analyzing tissue dynamics in other biological systems.

## Abstract

In this paper, we introduce an image analysis approach for spatiotemporal segmentation, quantification, and visualization of movement or contraction patterns in 2D+t and 3D+t microscopy recordings of biological tissues. The development of this pipeline was motivated by the observation of contraction waves in the extra-embryonic membranes of the red flour beetle Tribolium castaneum. These contraction waves are a novel finding, whose origin and function are not yet understood. The objective of the proposed approach is to analyze the dynamics of the extra-embryonic membranes in order to provide quantitative evidence for the existence of contraction waves during late stages of embryonic development.

We apply the pipeline to live-imaging data of Tribolium embryonic development recorded with light-sheet fluorescence microscopy. The proposed pipeline integrates particle image velocimetry (PIV) for quantitative movement analysis, surface detection, tissue cartography, and algorithmic identification of characteristic movement dynamics. We demonstrate that our approach reliably and efficiently detects contraction waves in both 2D+t and 3D+t recordings and enables automated quantitative analyses, such as measuring the area involved in contractile behavior, wave duration and frequency, spatiotemporal location of the contractile regions, and their relation to the underlying velocity distribution.

The pipeline will be employed in future work to conduct a large-scale characterization and quantification of contraction wave behavior in Tribolium development and can be readily adapted for the identification and segmentation of characteristic tissue dynamics in other biological systems.