Divergent immunity and energetic programs in the gills of migratory and resident Oncorhynchus mykiss.

Divergent life history strategies occur in steelhead or rainbow trout Oncorhynchus mykiss, and many populations produce both migrant (anadromous fish that move to the ocean after rearing) and resident (do not migrate and remain in fresh water) individuals. Mechanisms leading to each type are only partially understood; while the general tendency of a population is heritable, individual tendency may be plastic, influenced by local environment. Steelhead hatchery programmes aim to mitigate losses in wild stocks by producing trout that will migrate to the ocean and not compete with wild trout for limited freshwater resources. To increase our understanding of gill function in these migratory or resident phenotypes, here we compare gill transcriptome profiles of hatchery-released fish either at the release site (residents) or five river kilometres downstream while still in full fresh water (migrants). To test whether any of these genes can be used as predictive markers for smoltification, we compared these genes between migrant-like and undifferentiated trout while still in the hatchery in a common environment (prerelease). Results confirmed the gradual process of smoltification, and the importance of energetics, gill remodelling and ion transport capacity for migrants. Additionally, residents overexpressed transcripts involved in antiviral defences, potentially for immune surveillance via dendritic cells in the gills. The best smoltification marker candidate was protein s100a4, expression of which was highly correlated with Na(+) , K(+) ATPase (NKA) activity and smolt-like morphology in pre- and postrelease trout gills.

Testing advances in molecular discrimination among Chinook salmon life histories: evidence from a blind test.

The application of DNA-based markers toward the task of discriminating among alternate salmon runs has evolved in accordance with ongoing genomic developments and increasingly has enabled resolution of which genetic markers associate with important life-history differences. Accurate and efficient identification of the most likely origin for salmon encountered during ocean fisheries, or at salvage from fresh water diversion and monitoring facilities, has far-reaching consequences for improving measures for management, restoration and conservation. Near-real-time provision of high-resolution identity information enables prompt response to changes in encounter rates. We thus continue to develop new tools to provide the greatest statistical power for run identification. As a proof of concept for genetic identification improvements, we conducted simulation and blind tests for 623 known-origin Chinook salmon (Oncorhynchus tshawytscha) to compare and contrast the accuracy of different population sampling baselines and microsatellite loci panels. This test included 35 microsatellite loci (1266 alleles), some known to be associated with specific coding regions of functional significance, such as the circadian rhythm cryptochrome genes, and others not known to be associated with any functional importance. The identification of fall run with unprecedented accuracy was demonstrated. Overall, the top performing panel and baseline (HMSC21) were predicted to have a success rate of 98%, but the blind-test success rate was 84%. Findings for bias or non-bias are discussed to target primary areas for further research and resolution.

Pelvic Fragility Fractures: An Opportunity to Improve the Undertreatment of Osteoporosis.

BACKGROUND: Osteoporosis is often undiagnosed until patients experience fragility fractures. Pelvic fractures are common but underappreciated sentinel fractures. Screening patients with a pelvic fracture for osteoporosis may provide an opportunity to initiate appropriate treatments such as anti-osteoporosis therapy to prevent additional fractures. METHODS: This retrospective cohort review examined the management of osteoporosis after pelvic fractures at a large tertiary care center without an established secondary fracture prevention program. Data were extracted from electronic medical records of all new patients with a pelvic fracture who were ≥50 years of age from this center and its affiliated community hospitals from 2008 to 2014. Outcome measures included the initiation of anti-osteoporosis therapy before the fracture, within the year following the fracture, >1 year following the fracture, or never and new osteoporotic fractures within 2 years after a pelvic fracture. RESULTS: From 2008 to 2014, 947 patients presented with pelvic fractures. Of these patients, 27.1% (257 patients) were taking anti-osteoporosis medications before the fracture. Four percent of treatment-naïve patients began anti-osteoporosis therapy within 1 year of fracture, with 1.2% (11 patients) starting after 1 year. Of the treatment-naïve patients, 92.3% (637 patients) were never prescribed anti-osteoporosis therapy. Treatment rates were consistent over time. Within 2 years, 41.0% (388 patients) developed fragility fractures at secondary sites: 12.0% (114 patients) experienced a hip fracture, and 16.4% (155 patients) experienced a vertebral fracture. CONCLUSIONS: Osteoporosis screening and initiation of secondary fracture prevention after a pelvic fracture were inadequate in the study population. Of the patients in this study, 909 (96.0%) never underwent a dual x-ray absorptiometry (DXA) scan during the study period. Of the 690 treatment-naïve patients, 637 (92.3%) were never administered anti-osteoporosis medications. Within 2 years, 41.0% of all patients developed additional osteoporotic fractures. This study demonstrates an opportunity to improve bone health by screening for and treating osteoporosis in patients with a pelvic fragility fracture. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Use of sequence data from rainbow trout and Atlantic salmon for SNP detection in Pacific salmon.

Single nucleotide polymorphisms (SNPs) are a class of genetic markers that are well suited to a broad range of research and management applications. Although advances in genotyping chemistries and analysis methods continue to increase the potential advantages of using SNPs to address molecular ecological questions, the scarcity of available DNA sequence data for most species has limited marker development. As the number and diversity of species being targeted for large-scale sequencing has increased, so has the potential for using sequence from sister taxa for marker development in species of interest. We evaluated the use of Oncorhynchus mykiss and Salmo salar sequence data to identify SNPs in three other species (Oncorhynchus tshawytscha, Oncorhynchus nerka and Oncorhynchus keta). Primers designed based on O. mykiss and S. salar alignments were more successful than primers designed based on Oncorhynchus-only alignments for sequencing target species, presumably due to the much larger number of potential targets available from the former alignments and possibly greater sequence conservation in those targets. In sequencing approximately 89 kb we observed a frequency of 4.30 x 10(-3) SNPs per base pair. Approximately half (53/101) of the subsequently designed validation assays resulted in high-throughput SNP genotyping markers. We speculate that this relatively low conversion rate may reflect the duplicated nature of the salmon genome. Our results suggest that a large number of SNPs could be developed for Pacific salmon using sequence data from other species. While the costs of DNA sequencing are still significant, these must be compared to the costs of using other marker classes for a given application.