Thesis
Genetic alalysis [sic] of cortisol response in a wild X domestic rainbow trout cross
Washington State University
Master of Science (MS), Washington State University
2007
Handle:
https://hdl.handle.net/2376/101316
Abstract
Stressors in aquaculture can interfere with efficient fish production. Chronic stress decreases immune response, inhibits growth and negatively affects reproduction through various physiological pathways. It has been shown that stress response can be under strong genetic control, indicating the possibility for vast improvements in aquaculture broodstocks through breeding programs. Doubled haploids were created in a cross of our highly domestic Arlee (AR) and wild Whale Rock (WR) clonal lines. After 6 weeks on exogenous feed, seventy six doubled haploid progeny were individually exposed to a handling stressor and whole body cortisol levels were measured at 30 min. after termination of the stressor. Fish showing high cortisol response exhibited decreased body length ( r2 =0.131, p=0.001) and mass (r2 =0.099, p=0.005). A total of 453 polymorphic AFLP markers were used to create a genetic linkage map revealing 32 rainbow trout linkage groups at a marker density of one marker every 8.0cM. Composite interval mapping revealed 5 significant QTL, two for whole body cortisol levels, two for body length, and one for body mass. QTL for increased cortisol and short body length associated with the WR allele mapped to the same location on linkage group WA-XIV. A second cortisol QTL identified on the rainbow trout sex chromosome (WA-I) mapped in close association to the gene coding for carbonyl reductase, the analogue of a 20betahydroxysteroid dehydrogenase in rainbow trout, which is known to contribute to cortisol clearance. The identification of these regions influencing cortisol response may lead to mapping of stress-related genes, or marker assisted selection leading to a reduction in stress response and its associated negative effects.
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Details
- Title
- Genetic alalysis [sic] of cortisol response in a wild X domestic rainbow trout cross
- Creators
- Kyle Edward Martin
- Contributors
- Gary H. Thorgaard (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Biological Sciences, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525183301842
- Language
- English
- Resource Type
- Thesis