title: Characterization of the intronic VNTR polymorphisms found in a paralog of chicken serotonin transporter gene.
abstract: Polymorphisms in the neurotransmitter-related genes can be a major source of behavioral variations. We searched for polymorphic sites in chicken neurotransmitter-related genes and identified two variable number of tandem repeat (VNTR) loci encompassing the paralog of chicken serotonin transporter gene (5-HTT). Both intronic VNTR were highly polymorphic across chicken breeds and the other Galliformes species, even though predominant alleles were considerably different among breeds. One VNTR locus contained sequences complementary to a conserved motif of CCCTC-binding factor (CTCF) within each repetitive unit, indicating that transcription of chicken 5-HTT paralog may be regulated by the CTCF protein. It is of great interest to contrast these results with previous knowledge on the human 5-HTT that also has CTCF binding sites in the repetitive units of intronic VNTR. Additionally, we measured the degree of impulsiveness in domestic chicks for their preference of immediate/small to large/delayed rewards. A significant difference in the impulsiveness score was detected between two chicken breeds (White Leghorn vs. Boris Brown; P < 0.01), as well as between White Leghorn chicks with different 5-HTT genotypes. These findings imply the possibility that 5-HTT VNTR genotypes may have some impact on chicks' impulsive choice by modifying the serotonergic neurotransmission.
authors.affiliation: Wildlife Research Center, Kyoto University, Kyoto 606-8203, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Abe
authors.forename: Hiro-aki
authors.initials: HA
authors.lastname: Takeuchi
authors.forename: Satoko
authors.initials: S
authors.lastname: Yamada
authors.forename: Akihiro
authors.initials: A
authors.lastname: Nakamura
authors.forename: Kenji
authors.initials: K
authors.lastname: Nagao
authors.forename: Keijiro
authors.initials: K
authors.lastname: Nirasawa
authors.forename: Shin'ichi
authors.initials: S
authors.lastname: Ito
authors.forename: Miho
authors.initials: M
authors.lastname: Inoue-Murayama
mesh_terms: D000818:Animals; D001665:Binding Sites; D001947:Breeding; D002645:Chickens / Q000235:genetics*; D005838:Genotype; D007175:Impulsive Behavior / Q000235:genetics; D007438:Introns; D008297:Male; D018598:Minisatellite Repeats / Q000235:genetics*; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D020080:Tandem Repeat Sequences; D014158:Transcription, Genetic
chemical_list: D050486:Serotonin Plasma Membrane Transport Proteins