/ Watershed-based planning has been held as a vanguard for integrated ecosystem management based on a collaborative process. Watershed managers, however, must contend with conflicts that run much deeper than interests for economic development versus sustaining ecosystem health. With data from a survey of members of watershed organizations, we characterize the valued-based conflicts that watersh...

Intergenic transcription by RNA Polymerase II (Pol II) is widespread in plant and animal genomes, but the functions of intergenic transcription or the resulting noncoding transcripts are poorly understood. Here, we show that Arabidopsis Pol II is indispensable for endogenous siRNA-mediated transcriptional gene silencing (TGS) at intergenic low-copy-number loci, despite the presence of two other...

DNA polymerase ι (Pol ι) is an attractive candidate for somatic hypermutation in antibody genes because of its low fidelity. To identify a role for Pol ι, we analyzed mutations in two strains of mice with deficiencies in the enzyme: 129 mice with negligible expression of truncated Pol ι, and knock-in mice that express full-length Pol ι that is catalytically inactive. Both strains had normal fre...

Since its discovery and purification in 1971, DNA polymerase ß (Pol ß) is one of the most well-studied DNA polymerases. Pol ß is a key enzyme in the base excision repair (BER) pathway that functions in gap filling DNA synthesis subsequent to the excision of damaged DNA bases. A major focus of our studies is on the cellular roles of Pol ß. We have shown that germline and tumor-associated variant...

Mediator is a conserved multi-subunit complex known to promote the transcription of protein-coding genes by RNA polymerase II (Pol II) in eukaryotes. It has been increasingly realized that Pol II transcribes a large number of intergenic loci to generate noncoding RNAs, but the role of Mediator in Pol II-mediated noncoding RNA production has been largely unexplored. The role of Mediator in nonco...

A crucial step in transcription is the recruitment of RNA polymerase to promoters. In the transcription of human rRNA genes by RNA Polymerase I (Pol I), transcription factor SL1 has a role as the essential core promoter binding factor. Little is known about the mechanism by which Pol I is recruited. We provide evidence for an essential role for hRRN3, the human homologue of a yeast Pol I transc...

DNA polymerase kappa (Pol kappa) is a newly identified low-fidelity polymerase implicated in spontaneous and DNA damage-induced mutagenesis. As an initial study to investigate its possible involvement in tumorigenesis, we compared the expression level of Pol kappa in tumors and adjacent nontumorous tissues by Northern blot, semiquantitative RT-PCR, and Western blot analyses. In this study, pair...

On page 1191, Delbos and colleagues provide the first proof that the errorprone polymerase (pol ) is responsible for mutations at A-T base pairs during somatic hypermutation (SHM) of immunoglobulin (Ig) genes in mice. But when pol is removed from mice, another sloppy enzyme, not previously thought to contribute to SHM, can fill in as a pinch hitter. SHM generates high affinity antibodies in res...

Faithful transcription of DNA is constantly threatened by different endogenous and environmental genotoxic effects. Transcription coupled repair (TCR) has been described to stop transcription and quickly remove DNA lesions from the transcribed strand of active genes, permitting rapid resumption of blocked transcription. This repair mechanism has been well characterized in the past using individ...

Human cytomegalovirus (HCMV) utilizes RNA polymerase II to transcribe viral genes and produce viral mRNAs. It can specifically target the nucleolus to facilitate viral transcription and translation. As RNA polymerase I (Pol I)-mediated transcription is active in the nucleolus, we investigated the role of Pol I, along with relative contributions of the human Pol II and Pol III, to early phases o...