Plant & Animal Genomes XVI Conference Plant & Animal Genomes XVI ConferenceJanuary 12-16, 2008
Town & Country Convention Center
San Diego, CA
Kyle E. Martin , Gary H. Thorgaard , Robert E. Drew , Paul A. Wheeler
Stressors in aquaculture can interfere with efficient fish production. Chronic stress decreases immune response, inhibits growth and negatively affects reproduction by acting 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. Our highly domesticated clonal Arlee (AR) rainbow trout line, previously shown to have low cortisol response to stressors, was crossed with our wild Whale Rock (WR) clonal line to produce hybrids. These hybrids were used to produce doubled haploid progeny by androgenesis. Seventy six doubled haploid progeny were individually exposed to a handling stressor and whole body cortisol levels were measured at 30 min post stress event. 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 6.8cm. Composite interval mapping in our doubled haploid population revealed several loci with significant correlation to whole body cortisol levels at significance level of 0.05. The location and effect of these QTLs was compared to those in previously analyzed OSU X Arlee cross. 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.