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Evidence For An Epigenetic Mechanism By Which Hsp90 Acts As A Capacitor For Morphological Evolution, Vincent E. Sollars, Xiangyi Lu, Li Xiao, Xiaoyan Wang, Mark D. Garfinkel, Douglas M. Ruden
Evidence For An Epigenetic Mechanism By Which Hsp90 Acts As A Capacitor For Morphological Evolution, Vincent E. Sollars, Xiangyi Lu, Li Xiao, Xiaoyan Wang, Mark D. Garfinkel, Douglas M. Ruden
Vincent E Sollars
Morphological alterations have been shown to occur in Drosophila melanogaster when function of Hsp90 (heat shock 0-kDa protein 1α, encoded by Hsp83) is compromised during development1. Genetic selection maintains the altered phenotypes in subsequent generations1. Recent experiments have shown, however, that phenotypic variation still occurs in nearly isogenic recombinant inbred strains of Arabidopsis thaliana2. Using a sensitized isogenic D. melanogaster strain, iso-KrIf-1, we confirm this finding and present evidence supporting an epigenetic mechanism for Hsp90’s capacitor function, whereby reduced activity of Hsp90 induces a heritably altered chromatin state. The altered chromatin state is evidenced by ectopic expression of the morphogen …
Cladistic Relationships Of Aechmea (Bromeliaceae, Bromelioideae) And Allied Genera, A.P.G. De Faria, T. Wendt, Gregory K. Brown
Cladistic Relationships Of Aechmea (Bromeliaceae, Bromelioideae) And Allied Genera, A.P.G. De Faria, T. Wendt, Gregory K. Brown
Gregory K Brown
Aechmea (ca. 220 species) is the largest and most diverse genus in Bromelioideae (Bromeliaceae), and several dissimilar generic concepts and infrageneric classifications have been proposed, frequently involving other closely related Bromelioideae. A morphology-based phylogenetic analysis using parsimony was conducted with 86 taxa, including 52 Aechmea (7 of the 8 recognized subgenera represented) and 34 exemplars from 9 closely related genera as the ingroup. Two species of Cryptanthus were included as the outgroup. The main objectives were to assess the validity of the major infrageneric classification systems proposed for Aechmea and to elucidate the phylogenetic position of Aechmea and putatively related …