Skip to main content

Advertisement

Fig. 1 | BMC Evolutionary Biology

Fig. 1

From: Assessing the benefits of horizontal gene transfer by laboratory evolution and genome sequencing

Fig. 1

Experimental design of both evolution experiments. a We evolved multiple replicate populations of the K recipient strain on HPA for 60 serial transfer cycles (< 400 generations). Specifically, we established populations that we periodically exposed to W donor cells (6 replicate populations, \( \operatorname{Re}{\mathrm{c}}_{\mathrm{K}}^{\mathrm{W}} \)), to B donor cells (6 replicates, \( \operatorname{Re}{\mathrm{c}}_{\mathrm{K}}^{\mathrm{B}} \)), to K donor cells (6 replicates, \( \operatorname{Re}{\mathrm{c}}_{\mathrm{K}}^{\mathrm{K}} \)), and to no donor cells (6 replicates, RecK see Methods). b We evolved multiple replicate populations of the W recipient strain on butyric acid for 175 days (~ 1155 generations). Specifically, we established populations that we periodically exposed to B donor cells (6 replicate populations, \( \operatorname{Re}{\mathrm{c}}_{\mathrm{W}}^{\mathrm{B}} \)), to K donor cells (6 replicates, \( \operatorname{Re}{\mathrm{c}}_{\mathrm{W}}^{\mathrm{K}} \)), to W donor cells (6 replicates, \( \operatorname{Re}{\mathrm{c}}_{\mathrm{W}}^{\mathrm{W}} \)), and to no donor cells (6 replicates, RecW). For both experiments, we seeded the recipient populations from a single overnight culture of the ancestral recipient (gray cell cartoon at the left of each panel) grown in glycerol. Everyday, we transferred each evolving population to fresh growth medium (Additional file 35: Table S4) by 100-fold dilution (black arrows). Every five days, we prepared glycerol stocks, screened for contaminations, monitored adaptation via growth assays, and added the appropriate donor to the evolving population (Methods). Over the course of the experiment, we gradually replaced glycerol (dark yellow) with HPA (cyan) (a) or butyric acid (pink) (b) in the growth medium, until only the novel carbon source was present. Then, we evolved the populations for 10 more days in the novel carbon source to ensure that the populations could grow exclusively on the novel carbon source

Back to article page