Figure 2.

Compressed ATP6 molecular phylogeny in Saccharomyces sensu stricto species. ATP6 genes were identified from the mitochondrial genome sequences of 128 strains in 8 S. sensu stricto species examined, sequences of which were obtained from Strope et al. (2015), Leducq et al. (2017), Sulo et al. (2017). The rate variation model allowed for some sites to be evolutionarily invariable (+I; 84.3517% sites). The tree is drawn to scale, with branch lengths measured in the number of substitutions per site. All codon positions were included for analyses. All positions containing gaps and missing data were eliminated. Light brown shading denotes ENS2-containing groups. SpA, SpB, SpC, and SpC* correspond to the S. paradoxus population nomenclature of Leducq et al. (2017). The three S. paradoxus ATP6 groups (S. paradoxus groups 1 ATP6 ens2⁰, 2 ATP6 ens2⁰, and 3 ATP6-ens2) and six S. cerevisiae ATP6 groups (S. cerevisiae group 1 ATP6 ens2⁰, group 2 ATP6 ens2⁰, group 3 ATP6 ens2⁰, group 4 ATP6-ENS2, group 5 ATP6-ENS2, and group 1399 ATP6-ens2) are labeled. For the strains that comprise the three S. paradoxus ATP6 groups and the six S. cerevisiae ATP6 groups, see Figure S1, Figure S2, and Table S6.