Genetics of Adaptation of the Ascomycetous Fungus Podospora anserina to Submerged Cultivation.

Olga A Kudryavtseva,Aleksey A Penin,Tatiana V Neretina,Elena S Glagoleva,Georgii A Bazykin,Viktoria N Moskalenko,Maria D Logacheva,Alexey S Kondrashov,Ksenia R Safina,Olga A Vakhrusheva,Todd Vision

doi:10.1093/gbe/evz194

Abstract

Podospora anserina is a model ascomycetous fungus which shows pronounced phenotypic senescence when grown on solid medium but possesses unlimited lifespan under submerged cultivation. In order to study the genetic aspects of adaptation of P. anserina to submerged cultivation, we initiated a long-term evolution experiment. In the course of the first 4 years of the experiment, 125 single-nucleotide substitutions and 23 short indels were fixed in eight independently evolving populations. Six proteins that affect fungal growth and development evolved in more than one population; in particular, in the G-protein alpha subunit FadA, new alleles fixed in seven out of eight experimental populations, and these fixations affected just four amino acid sites, which is an unprecedented level of parallelism in experimental evolution. Parallel evolution at the level of genes and pathways, an excess of nonsense and missense substitutions, and an elevated conservation of proteins and their sites where the changes occurred suggest that many of the observed fixations were adaptive and driven by positive selection.

Highlights

Over the last several decades, experimental evolution became an essential part of evolutionary biology, providing an opportunity to observe and study changes that occur in controlled populations in the course of many generations
The existence of twelve replicas made it possible to study changes in genotypes and phenotypes that occurred in parallel in independently evolving bacterial populations [6,7,8]
Being cultured and fast-growing, E. coli serves as a convenient model organism for experimental evolution

Summary

Introduction

Over the last several decades, experimental evolution became an essential part of evolutionary biology, providing an opportunity to observe and study changes that occur in controlled populations in the course of many generations. The existence of twelve replicas made it possible to study changes in genotypes and phenotypes that occurred in parallel in independently evolving bacterial populations [6,7,8]. The range of questions that can be studied on it and on other prokaryotes is limited by their relative simplicity. Eukaryotes such as protozoans or fungi possess more complex gene regulation, morphology and physiology and have been used in the studies of experimental evolution [9,10,11,12]

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Results

Discussion

Conclusion