Positive Selection of Squalene Synthase in Cucurbitaceae Plants

Figure 2

Phylogenic tree of terrestrial plant SQS was inferred by Bayesian analyses and divided into five clades. Botryococcus braunii and Selaginella moellendorffii were used as outgroup A. Pteridophyte, Gymnosperms, Monocotyledons, and Dicotyledons were labeled as groups B, C, D, and E, respectively. Posterior probabilities are labeled above branches. Numbers indicate the Bayesian probabilities for each phylogenetic clade. Abbreviations of GpSS, TtSS, CmSS, TrSS, TkSS, CsSS, BhSS, MchSS, McSS, SgSS, and LaSS represent the squalene synthase of Gynostemma pentaphyllum, Trichosanthes truncata, Cucurbita moschata, Trichosanthes rubriflos, Trichosanthes kirilowii, Cucumis sativus, Benincasa hispida var. chieh-qua, Momordica charantia, Momordica cochinchinensis, Siraitia grosvenorii, and Luffa acutangula, respectively.