Mapping Data

Experiment

• Experiment
  TEXT-QTL-Candidate Genes
• Chromosome
  12
• Reference
  J:244215 Suzuki M, et al., Genetic dissection of the fatty liver QTL Fl1sa by using congenic mice and identification of candidate genes in the liver and epididymal fat. BMC Genet. 2016 Nov 17;17(1):145
• ID
  MGI:6111076

Genes

Gene	Assay Type
Fl1sa	visible phenotype
Ntsr2
Zfp125
Gdap10
Nrcam
Stxbp6
Nova1

Notes

• Experiment
  Nonalcoholic fatty liver disease (NAFLD) is a multifactorial disease caused by interactions between environmental and genetic factors.
  
  It was previously determined that SMXA-5 mice develop severe fatty liver on a high fat diet, although parental SM/J and A/J mice were resistant to fatty liver. Quantitative trait analysis using (SM/J x SMxA-5)F2 intercrossed mice identified a significant QTL, Fl1sa (fatty liver 1 in SMXA), for liver weight, liver triglyceride and total lipid content on centromere-53.06 Mb of mouse Chromosome 12. The A/J allele at Fl1sa was associated with the fatty liver. [J:124974] In a subsequent study using the livers from A/J-Chr 12^SM/J consomic and A/J mice that were fed a high fat diet three candidate genes were identified, Iah1, Rrm2 and Prkd1 using DNA microarray analysis. [J: 240255]
  
  The goal of the current study was to narrow the previously identified Fl1sa region by genetic dissection using novel congenic mice to identify candidate genes within the narrowed Fl1sa region. Two strains of congenic mice, A.SM-(centromere - D12Mit85)/J (R2) and A.SM-(D12Mit85-D12Mit112)/J (R3), were constructed from parental A/J and A/JChr 12 ^SM/J. Microsatellite markers and SNPs were used for the genotyping of R2 and R3 genomic DNA. Physical positions were taken from GRCm38.P4. The lipid accumulation in the respective livers was analyzed. As the liver triglyceride content in R2 and R3 congenic mice was significantly lower than in A/J mice.
  
  Male A/J, A/J-Chr12^SM/J, R2 and R3 mice were fed standard chow until 6 weeks of age and thereafter fed a high fat diet from 6 to 13 weeks of age. At 13 weeks of age all mice were sacrificed after a 4 hour fast. The liver and white adipose tissue (subcutaneous fat, epididymal fat, mesenteric fat and retroperitoneal fat) were harvested and weighed. Blood sample were collected to measure serum lipids. Serum triglyceride, cholesterol and hepatic triglyceride content were measured. Whole transcripts from epididymal fats were measured using a Mouse Genome ST 2.0 array.
  
  Liver triglyceride content was significantly lower in A/J-Chr 12^SM/J, R2 and R3 mice compared with that of A/J mice. Liver triglyceride and liver total lipid in R2 and R3 mice showed intermediate values between those of A/J and A/J-Chr 12 ^SM/J mice. The results suggested that the genes responsible for fatty liver existed in the SM/J region in strain R2 (centromere-29.20 Mb) and in the SM/J region in strain R3 (29.20-46.75 Mb) of Chromosome 12, Fig 1.
  
  Subsequently, in both of the narrowed Fl1sa regions microarray analysis of liver and epididymal fat from A/J and A/J-Chr 12 ^SM/J mice was performed in an attempt to identify candidate genes. Significant differences in gene expression levels in epididymal fat analysis were confirmed in 6 candidate genes: Ntsr2, Zfp125, Gdap10, Nrcam, Stxbp6 and Nova1 between the two strains.