Mapping rainbow trout immune genes involved in inflammation reveals conserved blocks of immune genes in teleosts.

We report the genetic map location of 14 genes involved in the inflammatory response to salmonid bacterial and viral pathogens, which brings the total number of immune genes mapped in rainbow trout (RT, Oncorhynchus mykiss) to 61. These genes were mapped as candidate genes that may be involved in resistance to bacterial kidney disease, as well as candidates for known QTL for resistance to infectious hematopoietic necrosis virus, infectious pancreatic necrosis virus and Ceratomyxa shasta. These QTL map to one or more of the linkage groups containing immune genes. The combined analysis of these linkage results and those of previously mapped immune genes in RT shows that many immune genes are found in syntenic blocks of genes that have been retained in teleosts despite species divergence and genome duplication events.

Recombination is suppressed over a large region of the rainbow trout Y chromosome.

The previous genetic mapping data have suggested that most of the rainbow trout sex chromosome pair is pseudoautosomal, with very small X-specific and Y-specific regions. We have prepared an updated genetic and cytogenetic map of the male rainbow trout sex linkage group. Selected sex-linked markers spanning the X chromosome of the female genetic map have been mapped cytogenetically in normal males and genetically in crosses between the OSU female clonal line and four different male clonal lines as well as in outcrosses involving outbred OSU and hybrids between the OSU line and the male clonal lines. The cytogenetic maps of the X and Y chromosomes were very similar to the female genetic map for the X chromosome. Five markers on the male maps are genetically very close to the sex determination locus (SEX), but more widely spaced on the female genetic map and on the cytogenetic map, indicating a large region of suppressed recombination on the Y chromosome surrounding the SEX locus. The male map is greatly extended at the telomere. A BAC clone containing the SCAR (sequence characterized amplified region) Omy-163 marker, which maps close to SEX, was subjected to shotgun sequencing. Two carbonyl reductase genes and a gene homologous to the vertebrate skeletal ryanodine receptor were identified. Carbonyl reductase is a key enzyme involved in production of trout ovarian maturation hormone. This brings the number of type I genes mapped to the sex chromosome to six and has allowed us to identify a region on zebrafish chromosome 10 and medaka chromosome 13 which may be homologous to the distal portion of the long arm of the rainbow trout Y chromosome.

Pattern of developing the performance template.

BACKGROUND: The pattern of energy expenditure during sustained high-intensity exercise is influenced by several variables. Data from athletic populations suggest that a pre-exercise conceptual model, or template, is a central variable relative to controlling energy expenditure. AIMS: The aim of this study was to make systematic observations regarding how the performance template develops in fit individuals who have limited specific experience with sustained high-intensity exercise (eg, time trials). METHODS: The study was conducted in four parts and involved measuring performance (time and power output) during: (A) six 3 km cycle time trials, (B) three 2 km rowing time trials, (C) four 2 km rowing time trials with a training period between trials 2 and 3, and (D) three 10 km cycle time trials. All time trials were self-paced with feedback to the subjects regarding previous performances and momentary pace. RESULTS: In all four series of time trials there was a progressive pattern of improved performance averaging 6% over the first three trials and 10% over six trials. In all studies improvement was associated with increased power output during the early and middle portions of the time trial and a progressively greater terminal rating of perceived exertion. Despite the change in the pattern of energy expenditure, the subjects did not achieve the pattern usually displayed by athletes during comparable events. CONCLUSIONS: This study concludes that the pattern of learning the performance template is primarily related to increased confidence that the trial can be completed without unreasonable levels of exertion or injury, but that the process takes more than six trials to be complete.

Effect of competitive distance on energy expenditure during simulated competition.

Concepts of how athletes should expend their aerobic and anaerobic energetic reserves are generally based on results of tests where an "all out" strategy is imposed on/required from the athlete. We sought to determine how athletes spontaneously expend their energetic reserves when the only instruction was to finish the event in minimal time, as in competition. Well trained, and task habituated, road cyclists (N = 14) completed randomly ordered laboratory time trials of 500 m, 1000 m, 1500 m and 3000 m on a windload braked cycle ergometer. The pattern of aerobic and anaerobic energy use was calculated from total work accomplished and V.O (2) during the trials. The events were completed in 40.3 +/- 0.6 s, 87.4 +/- 4.1 s, 133.8 +/- 6.6 s and 296.0 +/- 7.2 s. The peak V.O (2) during the terminal 200 m of all events was similar (2.72 +/- 0.22, 3.01 +/- 0.34, 3.23 +/- 0.44 and 3.12 +/- 0.13 l x min (-1)). In all events, the initial power output and anaerobic energy use was high, and decreased to a more or less constant value over the remainder of the event. However, the subjects seemed to reserve some ability to expend energy anaerobically for a terminal acceleration which is contrary to predictions of an "all out" starting strategy. Although the total work accomplished increased with distance (23.14 +/- 4.24, 34.14 +/- 6.37, 43.54 +/- 6.12 and 78.22 +/- 8.28 kJ), the energy attributable to anaerobic sources was not significantly different between the rides (17.29 +/- 3.82, 18.68 +/- 8.51, 20.60 +/- 6.99 and 23.28 +/- 9.04 kJ). The results are consistent with the concept that athletes monitor their energetic resources and regulate their energetic output over time in a manner designed to optimize performance.