The relationship between DRD4 polymorphisms and phenotypic correlations of behaviors in the collared flycatcher.
There is increasing evidence that the genetic architecture of exploration behavior includes the dopamine receptor D4 gene (DRD4). Such a link implies that the within-individual consistency in the same behavior has a genetic basis. Behavioral consistency is also prevalent in the form of between-individual correlation of functionally different behaviors; thus, the relationship between DRD4 polymorphism and exploration may also be manifested for other behaviors. Here, in a Hungarian population of the collared flycatcher, Ficedula albicollis, we investigate how males with distinct DRD4 genotypes differ in the consistent elements of their behavioral displays during the courtship period. In completely natural conditions, we assayed novelty avoidance, aggression and risk-taking, traits that were previously shown repeatable over time and correlate with each other, suggesting that they could have a common mechanistic basis. We identified two single-nucleotide polymorphisms (SNP554 and SNP764) in the exon 3 of the DRD4 gene by sequencing a subsample, then we screened 202 individuals of both sexes for these SNPs. Focusing on the genotypic variation in courting males, we found that "AC" heterozygote individuals at the SNP764 take lower risk than the most common "AA" homozygotes (the "CC" homozygotes were not represented in our subsample of males). We also found a considerable effect size for the relationship between SNP554 polymorphism and novelty avoidance. Therefore, in addition to exploration, DRD4 polymorphisms may also be associated with the regulation of behaviors that may incur fear or stress. Moreover, polymorphisms at the two SNPs were not independent indicating a potential role for genetic constraints or another functional link, which may partially explain behavioral correlations.
Department of Evolutionary Ecology, Estación Biológica de Doñana-CSIC Seville, Spain.
László Z
LZ
Garamszegi
Department of Behavioral Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology Seewiesen, Germany.
Jakob C
JC
Mueller
Behavioural Ecology Group, Department of Systematic Zoology and Ecology, Eötvös Loránd University Budapest, Hungary ; Department of Plant Pathology, Corvinus University of Budapest Budapest, Hungary ; Ecology Research Group, Hungarian Academy of Sciences, Hungarian Natural History Museum Budapest, Hungary.
Gábor
G
Markó
Behavioural Ecology Group, Department of Systematic Zoology and Ecology, Eötvös Loránd University Budapest, Hungary.
Eszter
E
Szász
Behavioural Ecology Group, Department of Systematic Zoology and Ecology, Eötvös Loránd University Budapest, Hungary ; Ecology Research Group, Hungarian Academy of Sciences, Hungarian Natural History Museum Budapest, Hungary ; Université Paris-Sud, Centre de Neurosciences Paris-Sud UMR 8195, Orsay, France.
Sándor
S
Zsebők
Behavioural Ecology Group, Department of Systematic Zoology and Ecology, Eötvös Loránd University Budapest, Hungary.
Gábor
G
Herczeg
Ethology Group, Department of Biology, University of Antwerp Wilrijk, Belgium.
Marcel
M
Eens
Behavioural Ecology Group, Department of Systematic Zoology and Ecology, Eötvös Loránd University Budapest, Hungary.
János
J
Török
Antipredator behavior; behavioral genetics; behavioral syndromes; linkage disequilibrium; novelty seeking; personality; temperament