Allopolyploid hybridization serves as a major pathway for plant evolution, but in its early stages it is associated with phenotypic and genomic instabilities that are poorly understood. We have investigated allopolyploidization between Arabidopsis thaliana (2n = 2x = 10; n, gametic chromosome number; x, haploid chromosome number) and Cardaminopsis arenosa (2n = 4x = 32). The variable phenotype of the allotetraploids could not be explained by cytological abnormalities. However, we found suppression of 20 of the 700 genes examined by amplified fragment length polymorphism of cDNA. Independent reverse transcription-polymerase chain reaction analyses of 10 of these 20 genes confirmed silencing in three of them, suggesting that approximately 0.4% of the genes in the allotetraploids are silenced. These three silenced genes were characterized. One, called K7, is repeated and similar to transposons. Another is RAP2.1, a member of the large APETALA2 (AP2) gene family, and has a repeated element upstream of its 5' end. The last, L6, is an unknown gene close to ALCOHOL DEHYDROGENASE on chromosome 1. CNG DNA methylation of K7 was less in the allotetraploids than in the parents, and the element varied in copy number. That K7 could be reactivated suggests epigenetic regulation. L6 was methylated in the C. arenosa genome. The present evidence that gene silencing accompanies allopolyploidization opens new avenues to this area of research.
In 2012 the Virginia Department of Transportation (DOT) Research Library conducted a trial of the electronic book database of EBSCO Information Services (EBSCO). The goals of the trial were to determine the level of interest by Virginia DOT employees in accessing e-books, to observe usage patterns and preferences of users in accessing content (EBSCO offered three access options for viewing onscreen or downloading to a personal device), to observe and gather usage statistics during the trial, to survey users on their experience and preferences for e-book devices, and to learn whether patrons used the library's subscriptions to the Books24×7, Knovel, or ASCE databases, which contain onscreen-only e-books. Usage statistics revealed high levels of interest in the e-book database. During the trial, 959 user sessions occurred, with 2,702 searches taking place, 694 e-books read onscreen, and 130 e-books checked out and downloaded to Adobe Digital Editions. Of the 32 respondents to a user satisfaction survey, 93.75% indicated that they would use e-books for their work or professional development; 39% found them somewhat easy or very easy to use; 63% read e-books onscreen; and 37% read from a portable e-book reader. Ninety percent of respondents had used other library full-text databases; 69% had purchased or received an e-book as a gift; and 40% had borrowed an e-book from another library. Research indicates that the EBSCO e-books database is a viable resource for Virginia DOT, provided that the proper content can be licensed and that adequate user education is provided.
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