Alteration of thyroid hormone concentrations in juvenile Chinook salmon (Oncorhynchus tshawytscha) exposed to polybrominated diphenyl ethers, BDE-47 and BDE-99.

Polybrominated diphenyl ethers (PBDEs) have been used as flame-retardants in consumer products and are currently detected in salmon globally. The two most predominant PBDE congeners found in salmon are BDE-47 (2,2',4,4'-tetrabromodiphenyl ether) and BDE-99 (2,2',4,4',5-pentabromodiphenyl ether). In the present study, groups of juvenile Pacific Chinook salmon were fed five environmentally relevant concentrations of either BDE-47 (0.

Dietary Exposure to Individual Polybrominated Diphenyl Ether Congeners BDE-47 and BDE-99 Alters Innate Immunity and Disease Susceptibility in Juvenile Chinook Salmon.

Polybrominated diphenyl ethers (PBDEs), used as commercial flame-retardants, are bioaccumulating in threatened Pacific salmon. However, little is known of PBDE effects on critical physiological functions required for optimal health and survival. BDE-47 and BDE-99 are the predominant PBDE congeners found in Chinook salmon collected from the Pacific Northwest.

Assimilation efficiency of PBDE congeners in Chinook salmon.

Polybrominated diphenyl ether (PBDE) flame retardants are environmental contaminants that can accumulate in biota. PBDE accumulation in an organism depends on exposure, assimilation efficiency, and elimination/metabolism. Net assimilation efficiency represents the fraction of the contaminant that is retained in the organism after exposure.

Toxicity of PHOS-CHEK LC-95A and 259F fire retardants to ocean- and stream-type Chinook salmon and their potential to recover before seawater entry.

Long-term fire retardants are used to prevent the spread of wildland fire, but have inadvertently entered aquatic habitats and resulted in fish kills. We examined the toxicity of two fire retardant products; PHOS-CHEK 259F and LC-95A, on Chinook salmon with two different life histories, ocean-type and stream-type, at different stages of their development. Ocean-type Chinook outmigrate to the ocean as subyearlings; while, stream-type salmon overwinter in freshwater and outmigrate as yearlings.

State of the environment in the arrangement area of the enterprises for repairing and utilization of nuclear-powered submarines.

The influence of nuclear-powered utilization (disjunction) upon the state of health of the soil, vegetation and atmospheric air was studied. It was stated that the concentration of hazardous metals in the air of an industrial site did not exceed the permissible levels. In the residential area the cases of increased concentrations of manganese and chromium were noted.

State of the environment in the arrangement area of the enterprises for repairing and utilization of nuclear-powered submarines.

The influence of nuclear-powered utilization (disjunction) upon the state of health of the soil, vegetation and atmospheric air was studied. It was stated that the concentration of hazardous metals in the air of an industrial site did not exceed the permissible levels. In the residential area the cases of increased concentrations of manganese and chromium were noted.

Organization of telomere sequences in birds: evidence for arrays of extreme length and for in vivo shortening.

Telomeres are the specialized ends of chromosomes consisting of highly conserved repeat (5'-TTAGGG-3')(n) sequences. Lack of information regarding the existence of an in vivo telomere clock function in birds, conflicting data regarding telomere array length in the chicken model, and the paucity of molecular telomere information for other avian species led us to study telomere array organization within and among 18 species and subspecies of birds. Most of the species contained between 2% and 4% telomere sequence per diploid genome.

Molecular characterization of ribosomal gene variation within and among NORs segregating in specialized populations of chicken.

The molecular organization of the 18S, 5.8S, and 28S ribosomal RNA gene repeat units, located at the single nucleolus organizer region (NOR) locus in the chicken, was investigated in genetically distinct populations of research and commercial chickens. Substantial gene repeat variation within and among NORs was documented.

Chloroplast DNA transgresses species boundaries and evolves at variable rates in the California closed-cone pines (Pinus radiata, P. muricata, and P. attenuata).

We studied phylogenetic relationships among populations and species in the California closed-cone pines (Pinus radiata D. Don, P. attenuata Lemm.