Mycena Genomes Resolve the Evolution of Fungal Bioluminescence

Author: mycolabadmin
2020-11-23
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Summary

This research investigated how certain mushrooms developed their ability to glow in the dark. Scientists discovered that this bioluminescent ability first evolved in mushrooms about 160 million years ago through a special group of genes called the luciferase cluster. While some mushroom species maintained this ability over time, many others lost it due to where these genes were located in their DNA. The study helps us understand how this fascinating natural phenomenon evolved and why it’s relatively rare among fungi today. Impacts on everyday life: – Helps explain the natural phenomenon of glowing mushrooms that people might encounter in forests – Provides insights that could be used to develop new bioluminescent technologies for lighting or imaging – Advances our understanding of how organisms evolve unique traits over millions of years – Could lead to applications in biotechnology and synthetic biology – Contributes to conservation efforts by helping us understand fungal biodiversity

Background

Bioluminescence in fungi is a fascinating trait found primarily in mushroom-forming species of the order Agaricales. The genus Mycena comprises around 600 small mushroom species worldwide, with 68 of 81 known bioluminescent fungi belonging to this genus. However, these represent less than 12% of all Mycena species, suggesting a complex evolutionary history of gaining and losing this trait. The mechanism involves a luciferase enzyme cluster, but the diversity, evolutionary history and timing of fungal luciferases remained unclear.

Objective

To investigate the evolution of fungal bioluminescence by sequencing and analyzing the genomes of five Mycena species (four bioluminescent and one non-bioluminescent) and conducting comparative genomic analyses with other bioluminescent fungi. The study aimed to understand how the luciferase gene cluster originated and was maintained or lost, determine variations in this cluster across lineages, and identify novel genes involved in bioluminescence.

Results

The study found that fungal bioluminescence evolved in the last common ancestor of mycenoid and marasmioid clades around 160 million years ago. The luciferase cluster was frequently rearranged and lost in most Mycena species but conserved in the Armillaria lineage. Analysis showed the cluster originated in low-synteny genomic regions making it susceptible to loss. Genome sizes varied significantly among Mycena species due to differential expansion of repeats controlled by DNA methylation. Luciferase cluster genes were coexpressed across developmental stages, with highest expression in fruiting body caps and stipes.

Conclusion

The research provides evidence for a single origin of fungal bioluminescence followed by extensive losses rather than multiple independent origins. The evolutionary dynamics of the luciferase cluster were influenced by its genomic location, with better preservation in stable genomic regions (Armillaria) versus frequent losses in dynamic regions (Mycena). The findings offer insights into how a gene cluster emerged 160 million years ago and was differentially maintained due to genome plasticity differences.

Published in:Proceedings of the National Academy of Sciences,
Study Type:Genomic Analysis,
Source: 10.1073/pnas.2010761117