Atlantic salmon (n = 1682) from 27 anadromous river populations and two nonanadromous strains ranging from south-central Maine, USA to northern Spain were genotyped at 12 microsatellite DNA loci. This suite of moderate to highly polymorphic loci revealed 266 alleles (5-37/locus) range-wide. Statistically significant allelic and genotypic heterogeneity was observed across loci between all but one pairwise comparison. Significant isolation by distance was found within and between North American and European populations, indicating reduced gene flow at all geographical scales examined. North American Atlantic salmon populations had fewer alleles, fewer unique alleles (though at a higher frequency) and a shallower phylogenetic structure than European Atlantic salmon populations. We believe these characteristics result from the differing glacial histories of the two continents, as the North American range of Atlantic salmon was glaciated more recently and more uniformly than the European range. Genotypic assignment tests based on maximum-likelihood provided 100% correct classification to continent of origin and averaged nearly 83% correct classification to province of origin across continents. This multilocus method, which may be enhanced with additional polymorphic loci, provides fishery managers the highest degree of correct assignment to management unit of any technique currently available.

Psychological factors should be taken into consideration in the treatment of patients with HD. High-SR patients with a negative patch-test seem to require more adjuvant psychological care.

The cause of deeply penetrating ulcers of Atlantic menhaden Brevoortia tyrannus has been the subject of significant research efforts in recent years. These lesions and the associated syndrome termed ulcerative mycosis have been observed along the East Coast of the United States since at least the early 1980s. Although Aphanomyces spp. were isolated from these lesions in the mid to late 1980s, similar lesions could not be reproduced by experimental infections of Atlantic menhaden with these isolates. The identical characteristic histologic appearance of granulomatous inflammation surrounding the penetrating fungal hyphae occurs in fish with epizootic ulcerative syndrome (EUS), as reported throughout South Asia, Japan, and Australia. Aphanomyces invadans has been found to be the causative agent of EUS in all of these countries. Using methods developed for the study of EUS, we successfully isolated an organism for which the DNA sequence, morphology, temperature and salinity growth characteristics, and infectivity of chevron snakehead Channa striata are identical to A. invadans. Using the polymerase chain reaction assay for A. invadans, we were able to demonstrate the presence of the organism from Atlantic menhaden lesions collected in U.S. estuarine waters from Delaware to South Carolina. In addition, the organism was present in lesions on a bluegill Lepomis macrochirus from a farm pond in Georgia and channel catfish Ictalurus punctatus from a farm pond in Louisiana.

We designed and tested real-time PCR probe/primer sets to detect and quantify Cytochrome b sequences of mitochondrial DNA (mtDNA) from nine vertebrate species of pet (dog), farm (cow, chicken, sheep, horse, pig), wildlife (Canada goose, white-tailed deer), and human. Linear ranges of the assays were from 10(1) to 10(8) copies/microl. To formally test the performance of the assays, twenty blinded fecal suspension samples were analyzed by real-time PCR to identify the source of the feces. Sixteen of the twenty samples were correctly and unambiguously identified. Average sensitivity was calculated to be 0.850, while average specificity was found to be 0.994. One beef cow sample was not detected, but mtDNA from 11 other beef cattle of both sexes and varying physiological states was found in concentrations similar (3.45 x 10(7) copies/g) to thatfound in human feces (1.1 x 10(7) copies/g). Thus, environmental conditions and sample handling are probably important factors for successful detection of fecal mtDNA. When sewage samples were analyzed, only human mtDNA (7.2 x 10(4) copies/ 100 mL) was detected. With a detection threshold of 250 copies/reaction, an efficient concentration and purification method resulted in a final detection limit for human feces of 1.8 mg/ 100 mL water.

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