title: Genetic dissection of susceptibility genes for diabetes and related phenotypes on mouse chromosome 14 by means of congenic strains.
abstract: BACKGROUND
  A susceptibility locus, Nidd2n, for type 2 diabetes has been mapped to mouse chromosome 14 (Chr 14) and confirmed using the consomic strain (C3H-Chr 14NSY) of the Nagoya-Shibata-Yasuda (NSY) mouse, an animal model of spontaneous type 2 diabetes. The aim of this study was to localize and characterize Nidd2n.
  
  
  RESULTS
  We constructed two novel congenic strains homozygous for different segments of NSY-Chr 14 on the control C3H/HeNcrj (C3H) background: R1 (C3H.NSY-(D14Mit206-D14Mit5)) possesses the proximal and middle segment, and R2 (C3H.NSY-(D14Mit206-D14Mit186)) possesses the most proximal segment of NSY-Chr 14. Diabetes-related phenotypes were studied in comparison with those of consomic C3H-Chr 14NSY (R0) and parental NSY and C3H strains. Congenic R1 and R2 showed significantly higher post-challenge glucose than that in C3H mice. Fasting glucose, in contrast, was significantly lower in R1 and R2 than in C3H mice. Insulin sensitivity was significantly impaired in R1 and R2 compared to C3H mice. R2 showed significantly higher body weight and fat-pad weight than those in C3H and R1. Leptin level was significantly higher in R0, R1 and R2 than in C3H mice, with R2 showing the highest level, similar to that in NSY mice. Serum adiponectin level was significantly lower in R0, R1 and R2 than in C3H mice, while it was significantly higher in NSY than in C3H mice.
  
  
  CONCLUSIONS
  These data indicate that Chr 14 harbors multiple genes for diabetes-related phenotypes. The original Nidd2n, which is located in the middle region of Chr 14, was divided into two segments; Nidd2.1n in proximal Chr 14 and Nidd2.2n in distal Chr 14. Nidd2.1n contributes to post-challenge hyperglycemia, insulin resistance and adiposity. Nidd2.2n contributes to fasting as well as post-challenge hyperglycemia and insulin resistance. Adp1n, which contributes to decreased adiposity and increased insulin sensitivity, rather than a diabetogenic gene, was mapped in the middle segment.
authors.forename: Naru
authors.initials: N
authors.lastname: Babaya
authors.forename: Hironori
authors.initials: H
authors.lastname: Ueda
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Noso
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Hiromine
authors.forename: Michiko
authors.initials: M
authors.lastname: Itoi-Babaya
authors.forename: Misato
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Tomomi
authors.initials: T
authors.lastname: Fujisawa
authors.affiliation: Department of Endocrinology, Metabolism and Diabetes, Kinki University School of Medicine, 377-2 Ohno-higashi, Osaka-sayama 589-8511, Osaka, Japan. ikegami@med.kindai.ac.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ikegami
mesh_terms: D050154:Adiposity / Q000235:genetics; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003920:Diabetes Mellitus / Q000235:genetics*; D004195:Disease Models, Animal; D005260:Female; D020022:Genetic Predisposition to Disease; D006943:Hyperglycemia / Q000235:genetics; D007333:Insulin Resistance / Q000235:genetics; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D020297:Mice, Congenic; D008809:Mice, Inbred C3H; D010641:Phenotype
chemical_list: D001786:Blood Glucose; D008565:Membrane Proteins; C586886:NIDD protein, mouse