Abstract Detail

Ecology/Pathology

Nagy, Laszlo [1], Hibbett, David [1].

Convergent regulatory evolution underlies the repeated appearance of yeast-like fungi.

Yeasts make up a polyphyletic assemblage of species with a pronounced unicellular phase in their lifestyle. They evolved several times in distantly related clades, in both the Asco- and Basidiomycota, yet the genetic bases of their evolution is not known. Phenotypic simplification associated with massive genome contractions is an attractive explanation, however, it fails to explain the level of similarity in the developmental program of distantly related yeast clades. Here, we show that the potential to develop yeast forms arose early in fungal evolution and has been conserved but latent in most clades. Yeast-like growth became the dominant growth form independently in multiple clades; these clades share the genes involved in yeast-like growth, which explains the similarities between unrelated yeast species. Our data suggest that the potential for yeast-like growth became pronounced most likely via parallel diversification of Zn-cluster transcription factors, a fungal-specific family involved in regulating yeast-filamentous switches. We conclude that convergent evolution of yeasts happened via a single origin of the genes involved in yeast-like growth, followed by repeated modification of their regulation is disparate clades, which ultimately led to clades of predominantly yeast-like fungi.

1 - Clark University, Biology Department, 950 Main street, Worcester, MA, 01610, USA

Keywords:
comparative genomics
yeast
convergent evolution
genome reduction
transcription factor.

Presentation Type: Offered Paper - Paper
Session: 16
Location: Room 104 AB/Kellogg Hotel and Conference Center
Date: Wednesday, June 11th, 2014
Time: 11:00 AM
Number: 16003
Abstract ID:109
Candidate for Awards:None