title: A functional variant in the 5'-flanking region of the chicken serotonin transporter gene is associated with increased body weight and locomotor activity.
abstract: In this study, we identified a polymorphism in the 5'-flanking region of the chicken serotonin transporter (5-HTT) gene. Sequencing analysis revealed that in comparison with the wild-type variant (W), a deleted variant (D) is generated by deletion of four nucleotides (5'-AATT-3') and a single nucleotide change (A→T). Using a polyacrylamide gel electrophoresis system, we found that the 360-bp DNA fragment containing the W variant with the wild-type sequence 5'-AATTAATT-3' shows intrinsic DNA curvature while the 356-bp fragment containing the D variant lacking the four base pairs AATT is not curved. Quantitative real-time RT-PCR and ELISA demonstrated that the expression of 5-HTT in D/D chickens was higher than that in W/W and W/D chickens. In addition, transient transfection experiments with chloramphenicol acetyltransferase reporter gene constructs revealed increased 5-HTT promoter activity mediated by the D variant and a silencer activity of the W variant. Interestingly, females and males with D/D genotype showed significant greater increase in body weight from 6 weeks and 16 weeks of age, respectively, and higher body mass index. Moreover, we found that D/D chickens of both genders were physically more active than W/W and W/D chickens.
authors.affiliation: Friedrich-Loeffler-Institut (FLI), Institute of Animal Welfare and Animal Husbandry, Celle, Germany.
authors.forename: Loc
authors.initials: L
authors.lastname: Phi-van
authors.forename: Marlis
authors.initials: M
authors.lastname: Holtz
authors.forename: Joergen B
authors.initials: JB
authors.lastname: Kjaer
authors.forename: Valerie D
authors.initials: VD
authors.lastname: van Phi
authors.forename: Katrin
authors.initials: K
authors.lastname: Zimmermann
mesh_terms: D024506:5' Flanking Region / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002645:Chickens; D005260:Female; D014644:Genetic Variation / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D009043:Motor Activity / Q000235:genetics*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D015430:Weight Gain / Q000235:genetics*
chemical_list: D050486:Serotonin Plasma Membrane Transport Proteins
keywords: 5-HTT; Serotonin; body weight; locomotor activity