Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.6 (RNA polymerase)
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Sequence data from the low-copy nuclear genes encoding phosphoribulokinase (PRK) and the second largest subunit of RNA polymerase II (RPB2) are used to generate the first phylogenetic analysis of Chamaedorea (Arecaceae: Arecoideae: Chamaedoreeae), the largest neotropical genus of palms. The prevailing current taxonomy of Chamaedorea recognizes approximately 100 species in eight subgenera, all delimited using floral characters, which provide a useful starting point to explore species-level systematics. Sequence data from 63 species, including representatives of all eight subgenera, were analyzed using maximum parsimony and Bayesian inference optimality criteria. Genus Chamaedorea is resolved as monophyletic with strong support in all separate and combined analyses. The less species-rich subgenera are convincingly monophyletic and can be diagnosed using morphological synapomorphies. In contrast, the two largest subgenera, Chamaedorea and Chamaedoropsis, which are supposedly distinguishable from each other by the degree of connation in the staminate petals, are both resolved as highly polyphyletic. Several well supported monophyletic groups resolved by these gene regions have never before been proposed within Chamaedorea and are challenging to delimit using morphological criteria. Although PRK proved more informative than RPB2, both regions have strong utility for interpreting species-level relationships among the palms, which are notoriously recalcitrant subjects for molecular phylogenetic studies. In addition, a paralog of the target copy of PRK identified during the analysis represents a potentially valuable source of phylogenetic information for future studies.
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PMID:Molecular phylogeny of the palm genus Chamaedorea, based on the low-copy nuclear genes PRK and RPB2. 1624 1

For the betel nut palm genus Areca and the other seven genera in subtribe Arecinae (Areceae; Arecoideae; Arecaceae) we collected DNA sequences from two low-copy nuclear genes, phosphoribulokinase (PRK) and the second largest subunit of RNA polymerase II (RPB2). The data were used to evaluate monophyly of the subtribe and its component genera, explore the radiation of the group across its range, and examine evolution of protandry and protogyny, which is particularly diverse in Arecinae. The subtribe and some genera are not monophyletic. Three lineages of Arecinae are recovered: one widespread, but centered on the Sunda Shelf, another endemic to the islands east of Wallace's line and a third, comprising the Sri Lanka endemic Loxococcus, that is most closely related to genera from outside subtribe Arecinae. Strong support is obtained for broadening the circumscription of the genus Hydriastele to include Gronophyllum, Gulubia and Siphokentia. In clarifying phylogenetic relationships, we have demonstrated that a perceived bimodal distribution of the subtribe across Wallace's line does not in fact exist. Character optimizations indicate that the evolution of protogyny, an unusual condition in palms, is potentially correlated with a large radiation in the genus Pinanga and possibly also to dramatic diversification in pollen morphology and genome size. The evolution of dichogamy in the clade endemic to the east of Wallace's line is complex and reveals a pattern of numerous transformations between protandry and protogyny that is in marked contrast with other Arecinae. We suggest that this contrast is most likely a reflection of differing geological histories and pollinator spectra in each region.
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PMID:Low-copy nuclear DNA, phylogeny and the evolution of dichogamy in the betel nut palms and their relatives (Arecinae; Arecaceae). 1662 10