Ethnopharmacological Relevance: Species of the genus Cinchona (Rubiaceae) have been used in traditional medicine, and as a source for quinine since its discovery as an effective medicine against malaria in the 17th century. Despite being the sole cure of malaria for almost 350 years, little is known about the chemical diversity between and within species of the antimalarial alkaloids found in the bark. Extensive historical Cinchona bark collections housed at the Royal Botanic Gardens, Kew, UK, and in other museums may shed new light on the alkaloid chemistry of the Cinchona genus and the history of the quest for the most effective Cinchona barks.
View Article and Find Full Text PDFMol Phylogenet Evol
February 2001
Species of Encarsia Förster (Hymenoptera: Aphelinidae, Coccophaginae) are economically important for the biological control of whitefly and armored scale pests (Hemiptera: Aleyrodidae, Diaspididae). Whereas some regional keys for identification of Encarsia species are now available, few studies have addressed relationships within this diverse and cosmopolitan genus because of unreliable morphological data. Nuclear sequences of the D2 expansion region of 28S rDNA were determined from 67 strains of 24 species representing 10 species groups of Encarsia, 2 strains of Encarsiella noyesi Hayat, and 1 strain of Coccophagoides fuscipennis Girault.
View Article and Find Full Text PDFA phylogeny of Bemisia tabaci is presented based on the ITS1 region of ribosomal DNA. The monophyly of each biotype of Bemisia is supported, and a strong biogeographic pattern is evident in the data. Populations from the Americas (including the A biotype) form a clade sister to a clade comprising the silverleafing or B biotype and a nonsilverleafing biotype from the North Africa/Mediterranean region.
View Article and Find Full Text PDFPrevious studies suggesting homology between human cellular DNA and the DNAs from adenovirus types 2 and 5 are extended in the present paper. A clone (ChAdh), isolated from a human genomic DNA library using an adenovirus probe, hybridized to discrete regions of adenovirus 2 DNA, including part of the transforming genes E1a and E1b, as well as to repeated sequences within human DNA. The E1a and E1b genes both hybridize to the same 300 base pair Sau3AI fragment within ChAdh although there is no obvious homology between E1a and E1b.
View Article and Find Full Text PDF