Download or read book Effect of Domestication on Competitive Behavior and Associated Gene Expression written by Soniya Balli and published by . This book was released on 2016 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rainbow trout (oncorhynchus mykiss) are important aquaculture fish that had been recently domesticated since the late 19th century. Various studies show that captive reared populations of rainbow trout show genetic, physiological and behavioral changes when compared with their wild counterparts. this research investigated the effect if domestication on competitive behavior at three different levels; behavior, quantitative gene expression and spacial gene expression. We used separate outbred hybrid progeny derived from three wild strains, Swanson, Klamath and Whale Rock and two domesticated strains, Arlee and Hot Creek to study behavior and quantitative gene expression. Two similar competitive experiments were conducted for nine days and two days. Strain specific differences in behavioral traits were detected. In the first competition experiment; Swanson showed increased motivation to feed in the presence of a conspecific competitor unlike other strains. In the second competition experiment; Arlee and Hot Creek were more active and occupied positions closer to the food source than the wild strains after one day. Differences in competitive abilities across populations may be influenced by domestication history, geographical location of origin, choice of traits measured and the length of the competition experiment. Quantitative gene expression analyses were carried out on the samples from the competition experiments using quantitative polymerase chain reaction. Strain specific relationships between difference in target gene expression and differences in behavioral traits were detected in the samples from the first competition experiment. Arlee showed significantly different relationships between the expression of crh and avt with respect to feeding activity when compared with that of Swanson and Hot Creek. This change detected in Arlee may be due to the effect of adaptation to the local environment from where it was originally isolated or due to the combination of those factors with the effect of domestication. No significant variations in target gene expression associated with behavioral traits was detected in the samples derived from the second competition experiment. Spatial expression pattern of selenoprotein P (sepp l a) in adult zebrafish was detected to test the hypothesis that quantitative differences in gene expression may be associated with differences in the number of cells expressing them using in situ hybridization technique. The technique was developed to test the hypothesis in wild and domesticated populations of rainbow trout strains. sepp l a was expressed in regions of the diencephalon, mesencephalon and the cerebellum. Due to technical errors, the hypothesis was not tested but the technique was developed for future investigations. The strains of rainbow trout used in the present study are being extensively utilized to map quantitative behavioral loci (QTL) associated with complex behavioral traits like stress response and growth. Investigations from current study will add additional insights for future exploration on genome level variation to identify different levels by which populations undergo adaptations in captivity and understand and potentially alleviate their impact on the wild populations upon escape from captivity or intentional release for conservation purposes.