title: Relationship between seasonal cold acclimatization and mtDNA haplogroup in Japanese.
abstract: BACKGROUND
  The purpose of this study was to elucidate the interaction between mtDNA haplogroup and seasonal variation that contributes to cold adaptation.
  
  
  METHODS
  There were 15 subjects (seven haplotype D subjects and eight haplotype non-D subjects). In summer and winter, the subjects were placed in an environment where the ambient temperature dropped from 27 °C to 10 °C in 30 minutes. After that, they were exposed to cold for 60 minutes.
  
  
  RESULTS
  In summer, the decrease in rectal temperature and increase in oxygen consumption was smaller and cold tolerance was higher in the haplotype non-D group than in the haplotype D group. In winter, no significant differences were seen in rectal temperature or oxygen consumption, but the respiratory exchange ratio decreased in the haplotype D group.
  
  
  CONCLUSIONS
  The results of the present study suggest that haplogroup D subjects are a group that changes energy metabolism more, and there appears to be a relationship between differences in cold adaptability and mtDNA polymorphism within the population. Moreover, group differences in cold adaptability seen in summer may decrease in winter due to supplementation by seasonal cold acclimatization.
authors.affiliation: Kyushu University, Fukuoka, 815-8540, Japan. takayuki@gsd.design.kyushu-u.ac.jp
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nishimura
authors.forename: Midori
authors.initials: M
authors.lastname: Motoi
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Niri
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Hoshi
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Kondo
authors.forename: Shigeki
authors.initials: S
authors.lastname: Watanuki
mesh_terms: D000064:Acclimatization / Q000235:genetics*; D000273:Adipose Tissue / Q000502:physiology; D000704:Analysis of Variance; D001830:Body Surface Area; D001831:Body Temperature / Q000235:genetics; D003080:Cold Temperature; D004272:DNA, Mitochondrial / Q000235:genetics*; D006239:Haplotypes / Q000235:genetics*; D006801:Humans; D007564:Japan; D010101:Oxygen Consumption / Q000235:genetics / Q000502:physiology; D016133:Polymerase Chain Reaction; D012007:Rectum / Q000502:physiology; D012621:Seasons
chemical_list: D004272:DNA, Mitochondrial