DOI: 10.5061/dryad.zcrjdfnnk
title: Myxococcus xanthus cellular structures during early development

description: Aggregation underlies collective dynamics of a diversity of organisms,
 enabling the formation of complex structures and emergent behaviours in
 interaction with the environment. Cellular aggregation constitutes one of
 the routes to collective motility and multicellular development.
 Myxococcus xanthus, a social bacterium, is a valuable model for studying
 the aggregative way to multicellularity, a major transition in the
 evolutionary history of life. While the collective developmental behaviour
 of M. xanthus has been largely studied in  high cellular
 densities, there is a lack of understanding at low density conditions that
 can be ecologically relevant. In this work, we study the early stages of
 emergent collective behaviour of M. xanthus under nutrient-poor and low
 density conditions, uncovering the formation of diverse cellular
 structures with different shapes and sizes, ranging from individual cells
 to networks comprising thousands of cells. We study their motility
 patterns and their prevalence along development, and discuss their
 cross-scale role on the population’s exploratory dynamics. This work
 contributes to understanding key, yet largely understudied, aspects in the
 early stages of multicellular development in myxobacteria, shedding light
 on the dynamics underlying aggregative processes in this and other taxa
 and study systems.  
description: The samples were observed through TPM agar medium using an
 inverted optical microscope with a 10X objective lens (Olympus UPlanSApo
 series, 0.4 NA), illuminated with amber light and recorded with a Basler
 acA 1600-20uc with overall resolution of 0.52 μm/pixel and 1000 μm x 624
 μm field of vision. The microscope was set inside an isolated chamber with
 a controlled temperature of 28 C. Micrographs were taken for two of the
 three replicates, while 15 min videos were taken at t=0, 4 and 8 h from
 the onset of starvation (after the spots dried) for the third replica at
 an acquisition rate of 1 frame per second. Micrographs and video frames
 were binarized using segmentation through edge-detection and
 intensity-threshold criteria implemented with the Image Processing Toolbox
 of MATLAB.  Analysis from the resulting database was conducted using R
 v.4.2.0.  <br><br>
description: # Myxococcus xanthus Cellular structures during early development
 [https://doi.org/10.5061/dryad.zcrjdfnnk](https://doi.org/10.5061/dryad.zcrjdfnnk) ## Description of the data and file structure The samples were observed through TPM agar medium using an inverted optical microscope with a 10X objective lens (Olympus UPlanSApo series, 0.4 NA), illuminated with amber light, and recorded with a Basler acA 1600-20uc with an overall resolution of 0.52 μm/pixel and 1000 μm x 624 μm field of vision. The microscope was set inside an isolated chamber with a controlled temperature of 28 C. Micrographs were taken for two of the three replicates, while 15 15-minute videos were taken at t=0, 4, and 8 h from the onset of starvation (after the spots dried) for the third replica at an acquisition rate of 1 frame per second. Micrographs and video frames were binarized using segmentation through edge-detection and intensity-threshold criteria implemented with the Image Processing Toolbox of MATLAB.  Area (area of each structure) and Total_area (sum of the area of all structures in the micrograph or a video frame) are presented in µm2. Analysis from the resulting database was conducted using R v.4.2.0.  ### Files and variables #### File: Database\_BiolLett\_Rivera-Yoshida-R.csv **Description:** Myxococcus xanthus developmental structures ##### Variables * Name * Density * Hours  * Total_area * Area * Replica ## Code/software statistical analysis was conducted in R using the libraries plyr, dplyr, ggplot2, ggpubr, tidyverse and webr