Title

Behavioral Genetic Characterization of Hunting in Domestic Dogs, Canis Familiaris

Date of Award

2011

Document Type

Dissertation

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Biological Sciences

First Advisor

Robert Huber (Committee Chair)

Second Advisor

Moira van Staaden (Committee Member)

Third Advisor

Paul Morris (Committee Member)

Fourth Advisor

Verner Bingman (Committee Member)

Abstract

Humans have exerted strong selection pressures for the behavioral attributes which make dogs prized hunting companions, viz., superior sensory capabilities, social cognition, and tenacious pursuit of prey. With behavioral traits maintained in stable breed lines, and a unique genome organization, dogs are ideally suited for a genetic dissection of complex behavioral phenotypes. Despite studies employing substantial sampling regimes the promise of the canine model has yet to be realized, largely because of the dearth of robust quantitative behavioral metrics. Here we show that refined dissection of a complex behavior into component parts is instrumental in identifying genomic signatures associated with these elements. Using 11 spatially explicit measures we demonstrate the existence of four principal dispositions describing Search Eagerness, Linear Running, Handler Reliance, and Zigzagged Searching. A Single Nucleodide Polymorphic marker - based association study reveals that Search Eagerness significantly associates with genomic regions on chromosomes 1 and 27 (Chromosome wide significance, p [100,000 permutations] < 0.05). Adjacent are sites for brain specific Demethylase- (MBD2) and GABA transporter genes (BGT1, GAT2, GAT3) coding for transcriptional repressor proteins and regulating levels of extracellular neurotransmitters respectively. We anticipate that the wider application of such objective quantitative frameworks will improve the phenotypic characterization that remains the bottleneck in neurobehavioral genetic research.