Genetic polymorphism in dopamine receptor D4 is associated with early body condition in a large population of greater flamingos, Phoenicopterus roseus

Abstract

Body condition is an important determinant of fitness in many natural populations. However, as for many fitness traits, the underlying genes that regulate body condition remain elusive. The dopamine receptor D4 gene (DRD4) is a promising candidate as dopamine is known to play an important role in the regulation of food intake and the metabolism of both glucose and lipids in vertebrates. In this study, we take advantage of a large data set of greater flamingos, Phoenicopterus roseus, to test whether DRD4 polymorphism predicts early body condition (EBC) while controlling for whole-genome effects of inbreeding and outbreeding using microsatellite multilocus heterozygosity (MLH). We typed 670 of these individuals for exon 3 of the homologue of the human DRD4 gene and 10 microsatellite markers. When controlling for the effects of yearly environmental variations and differences between sexes, we found strong evidence of an association between exon 3 DRD4 polymorphisms and EBC, with 2.2-2.3% of the variation being explained by DRD4 polymorphism, whereas there was only weak evidence that MLH predicts EBC. Because EBC is most likely a polygenic trait, this is a considerable amount of variation explained by a single gene. This is to our knowledge, the first study to show an association between exon 3 DRD4 polymorphism and body condition in non-human animals. We anticipate that the DRD4 gene as well as other genes coding for neurotransmitters and their receptors may play an important role in explaining variation in traits that affect fitness.

The relationship between DRD4 polymorphisms and phenotypic correlations of behaviors in the collared flycatcher

“…We identified two SNPs of the DRD4 orthologue in a wild collared flycatcher population. The genotype frequencies were comparable with the unequal proportion of genotypes detected in other bird species for other DRD4 orthologues Fidler et al 2007;Korsten et al 2010;Gillingham et al 2012;Carvalho et al 2013; but see Kluen et al 2012 for more or less equal allele frequencies). We related this genetic variation to phenotypic variations in behavior.…”

Variation at the DRD4 locus is associated with wariness and local site selection in urban black swans

“…[ 35 ]) or body condition (e.g. [ 36 ]). Alternatively, linkage disequilibrium may result in the SNPs detected in this study being linked to SNPs at other genes which also regulate fear, such as the SERT gene.…”

“…All others were assumed to be sequencing artefacts. Following [ 36 ], we then identified unique alleles that differed from all other alleles by at least one SNP and assigned genotypes to each individual based on the identity of their two alleles. The unique DRD4 alleles generated for this study were then submitted to GenBank [GenBank: KM390804-KM390808].…”

Evidence for an Association between Post-Fledging Dispersal and Microsatellite Multilocus Heterozygosity in a Large Population of Greater Flamingos

“…Thus a random sample of chicks, which included early- and late-hatching birds, was captured (approximate age range 35–77 days) [26] . During ringing operations, we measured tarsus length to the nearest 1 mm and body weight to the nearest 50 g using a 5-kg Pesola spring balance (see Johnson & Cézilly [26] for details) and we collected blood samples for DNA extraction and sexing (for details see Gillingham et al [27] ). Chicks were also marked individually with PVC plastic rings engraved with a four-digit code which can be read at up to 300 m. Greater flamingos lay only one egg per season, systematically switch mates between consecutive seasons and show strong age-assortative mating [26] , [28] , [29] , excluding any full-sibling relationships in the present study.…”

“…In addition to the 670 individuals genotyped by Gillingham et al [27] , 353 more individuals (a total of 1023) were genotyped for ten microsatellite loci (PrD3, PrD4, PrD5, PrD9, PrA110, PrA113, PrC109, PrD108, PrD121 and PrD126) developed for the greater flamingo (see [27] or details of microsatellite genotyping). For each cohort, the program MICRO-CHECKER [35] was used to test for genotyping errors.…”