Disentangling the multiple drivers of ecological adaptation in a microorganism

The survival and reproduction of living organisms depend on their ability to achieve an adequate balance between energy intake and energy expenditure. Multiple quantities contribute to this energetic balance, such as the feeding rate, and the allocation of available energy to growth, maintenance, movement, and reproduction. Given that many of these quantities scale in a predictable way with the size of the organism and with environmental parameters, it should be possible to predict how organisms may adapt to novel environmental conditions in terms of adjusting their morphology, physiology, and behaviour. In a series of experiments, we adapted axenic experimental populations of the ciliate Tetrahymena pyriformis to different environmental conditions of temperature (15°C, 20°C and 25°C) and resource levels (50%, 100%, and 200% of a standard protein solution). We measured population growth, metabolic rate (from respiration), cell size, and movement speed (from video-tracking). On a very sh..., Cell cultures
Axenic cultures of Tetrahymena pyriformis strain 1630/1W were obtained from CCAP (www.ccap.ac.uk) and cultured at 20 degrees Celsius in a Proteose peptone - yeast extract medium 20 g Proteose peptone + 2.5 g yeast extract in 1L deionized water. Cells were maintained in the exponential growth phase at 20°C and 100% medium concentration for about 50 days (constant temperature, no light) in two replicates. Subsequently, cultures were split across 9 different treatments (3 temperature conditions x 3 medium concentrations) and adapted to the new conditions for at least three weeks (corresponding to a minimum of 20 generations), in four replicates for each condition.
Throughout the entire duration of the adaptation period, cultures were kept in relatively constant growing conditions by adopting a serial transfer regime, subculturing repeatedly into fresh growth medium. At the end of the adaptation period, cultures were further split across a wide range of temperature conditions ..., , # Disentangling the multiple drivers of ecological adaptation in a microorganism

[https://doi.org/10.5061/dryad.2v6wwpzvv](https://doi.org/10.5061/dryad.2v6wwpzvv)

Please refer to the original manuscript for details of methods. The code provided is meant to directly read the CSV data files with column names and other information as provided.

## Description of the data and file structure

Video tracking and analysis of the movement of *Tetrahymena pyriformis*

This repository contains the code (mostly R) associated with the manuscript

[https://doi.org/10.1101/2023.07.25.550219](https://doi.org/10.1101/2023.07.25.550219)

The data are also in the repository.

The **video_tracking folder** contains the Python scripts used for tracking *Tetrahymena* cells from videos recorded under the microscope. If the scripts are used on different videos it might be necessary to change file paths and also some parameters such as the frame rate, and the scale for converting video pixels to units of le...