DNA methylation and expression of estrogen receptor alpha in fathead minnows exposed to 17α-ethynylestradiol.

The gene expression response thought to underlie the negative apical effects resulting from estrogen exposure have been thoroughly described in fish. Although epigenetics are believed to play a critical role translating environmental exposures into the development of adverse apical effects, they remain poorly characterized in fish species. This study investigated alterations of DNA methylation of estrogen receptor alpha (esr1) in brain and liver tissues from 8 to 10 month old male fathead minnows (Pimephales promelas) after a 2d exposure to either 2.

Validating sonication as a DNA extraction method for use with carrion flies.

Entomological evidence can be critical in establishing a postmortem interval estimate. DNA-based species identification can be an extremely valuable tool for forensic entomology. The problem of processing samples in a consistent, cost-effective manner that retains the morphological attributes of the specimen for vouchering has led us to investigate sonication as a primary means of non-destructive DNA extraction from carrion flies.

Mutations to Less-Preferred Synonymous Codons in a Highly Expressed Gene of Escherichia coli: Fitness and Epistatic Interactions.

Codon-tRNA coevolution to maximize protein production has been, until recently, the dominant hypothesis to explain codon-usage bias in highly expressed bacterial genes. Two predictions of this hypothesis are 1) selection is weak; and 2) similar silent replacements at different codons should have similar fitness consequence. We used an allele-replacement strategy to change five specific 3rd-codon-position (silent) sites in the highly expressed Escherichia coli ribosomal protein gene rplQ from the wild type to a less-preferred alternative.

Sequencing human mitochondrial hypervariable region II as a molecular fingerprint for environmental waters.

To protect environmental water from human fecal contamination, authorities must be able to unambiguously identify the source of the contamination. Current identification methods focus on tracking fecal bacteria associated with the human gut, but many of these bacterial indicators also thrive in the environment and in other mammalian hosts. Mitochondrial DNA could solve this problem by serving as a human-specific marker for fecal contamination.

Microbial survey of a full-scale, biologically active filter for treatment of drinking water.

The microbial community of a full-scale, biologically active drinking water filter was surveyed using molecular techniques. Nitrosomonas, Nitrospira, Sphingomonadales, and Rhizobiales dominated the clone libraries. The results elucidate the microbial ecology of biological filters and demonstrate that biological treatment of drinking water should be considered a viable alternative to physicochemical methods.