Differences in DRD4 in Carolina chickadees and black-capped chickadees

BAINS, ASHVEEN; FERRETTI VALENTINA; CURRY, ROBERT

Villanova

Jornada; Villanova Undergraduate Research Fellows Program; 2012

Personality in animals plays a role in evolution because differences in behavioral phenotypes will affect how an animal interacts with its environment, ultimately affecting its chances for survival and reproduction.. To accurately understand the significance of personality in animals ecologically and evolutionarily, we need to understand the molecular basis of personality. Studies in mammals and a few bird species have shown that polymorphisms in the Dopamine Receptor D4 (DRD4) gene are responsible for variation in personality. We studied polymorphisms in DRD4 in individuals of two species of birds that hybridize, black-capped chickadees (Poecile atricapillus) and Carolina chickadees (P. carolinensis). We investigated this variation in DRD4 in two populations in southeastern Pennsylvania: Great Marsh, with Carolina chickadees, and Tuscarora, with black-capped chickadees. From each adult bird caught at these two sites we took a blood sample for DNA analyses. In total we extracted DNA from 97 Carolina chickadees and 45 black-capped chickadees caught in 2012 as well as in previous years. We used these extracts to amplify two fragments of the DRD4 gene to determine genetic polymorphism (SNP830C/T and ID15). We sequenced the amplified fragments and assembled the DNA sequences to look at the genetic composition of each bird. We detected species differences in the frequencies of ID15 genotypes but no differences were detected in the frequencies of SNP830C/T. The next step will be for us to look at whether the genetic polymorphisms detected are correlated with variation in personality traits.