Polymorphism of dopamine receptor D4 exon I corresponding region in chicken.
In stockbreeding, there are indications that behavioral traits of livestock have an effect on breeding and production. If the variation in individual behavior is related to that in neurotransmitter-related genes such as in humans, it would be possible to breed pedigrees composed of individuals having behavioral traits that are useful to production and breeding using selection based on genotypes. In this study, we investigated the exon I region of dopamine receptor D4 (DRD4), in which variation is related to psychiatric disorder in humans, in major poultry species namely Japanese quail (Coturnix japonica), chicken (Gallus gallus), ring-necked pheasant (Phasianus colchicus) and helmeted guinea fowl (Numida meleagris). Furthermore, we investigated Japanese cormorant (Phalacrocorax capillatus) and Japanese jungle crow (Corvus macrorhynchos) as an out-group. In these species of birds, the repeat of proline was identified in the region corresponding to the human polymorphic region. The repeat number was 9 in Japanese quail, ring-necked pheasant and Japanese cormorant; 12 in helmeted guinea fowl; and 3 in Japanese jungle crow. However, no polymorphism was found in these species. In contrast, polymorphism was observed in chicken and two alleles with 8 and 9 repeats were identified. Although 9 repeats (allele 9) were predominant in most chicken breeds, Black Minorca had only 8 repeats (allele 8). Intra-breed polymorphism was found in 6 out of 12 breeds, and two alleles (alleles 8 and 9) were detected in these breeds. This polymorphism, which is the first to be reported on a neurotransmitter-related gene in birds, would contribute significant information for elucidation of differences in behavioral traits in chicken breeds.
Faculty of Applied Biological Sciences, Gifu University, Japan.
Akinori
A
Sugiyama
Miho
M
Inoue-Murayama
Mitsuru
M
Miwa
Riyako
R
Ohashi
Boniface Baboreka
BB
Kayang
Makoto
M
Mizutani
Keijiro
K
Nirasawa
Masaharu
M
Odai
Mitsuru
M
Minezawa
Shigeru
S
Watanabe
Shin'ichi
S
Ito
D000595:Amino Acid Sequence; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D001717:Birds / Q000235:genetics; D001947:Breeding / Q000379:methods; D002645:Chickens / Q000235:genetics*; D005091:Exons / Q000235:genetics*; D005784:Gene Amplification; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D050638:Receptors, Dopamine D4; D012641:Selection, Genetic
C493599:DRD4 protein, human; D017448:Receptors, Dopamine D2; D050638:Receptors, Dopamine D4