Mapping Data

Experiment

• Experiment
  TEXT-QTL
• Chromosome
  1
• Reference
  J:4733 Mehrabian M, et al., Influence of the apoA-II gene locus on HDL levels and fatty streak development in mice [published erratum appears in Arterioscler Thromb 1993 Mar;13(3):466]. Arterioscler Thromb. 1993 Jan;13(1):1-10
• ID
  MGI:3521665

Genes

Gene	Assay Type
Mtv27	reported elsewhere
Apoa2	reported elsewhere
Fcgr2b	reported elsewhere
Spta1	reported elsewhere
Lprq3	visible phenotype

Notes

• Experiment
  15 NXSM (N= NZB/BlNJ; SM=SM/J) recombinant in bred (RI) strains were examined for plasma lipid traits. Female animals were placed on CHOW or high fat diets and then sacrificed for lipid analysis. Parental strain NZB/BlNJ exhibits elevated HDL cholesterollevels compared to parental strain SM/J.
  
  Marker Mtv27 (96.8 cM) on mouse Chromosome 1 shows linkage to HDL cholesterol (P<0.0004) on a CHOW diet. This locus is named Lprq3 (lipoprotein QTL 3). NZB/BlNJ-derived alleles confer increased HDL cholesterol levels at Lprq3. A major candidate gene located directly under the area of peak linkage is Apoa2 (92.6 cM). Lprq3 was confirmed in a panel of BXD RI strains. Apoa2 gave peak linkage to HDL cholesterol levels (LOD=3.7) on a CHOW diet in the BXD RI population. Lprq3 explains 74% of the phenotypic variance.
  
  The Apoa2 locus map close to another HDL-related QTL named Tnfsf4 (90.1 cM). To determine if the Apoa2 locus and Tnfsf4 are the same QTL the congenic strain B6.C-H25^c/(HW65)ByJ was examined. This congenic carries BALB/cJ-derived alleles from Fcgr2b (92.3 cM) to Spna1 (95.4 cM). Apoa2 is contained within the congenic region while Tnfsf4 is outside of the congenic region. (Donor strain BALB/cJ exhibits high HDL cholesterol on a high fat diet compared to C57BL/6J.) The B6.C-H25^c/(HW65)ByJ congenic exhibits increased HDL cholesterol on a high fat diet compared to background strain C57BL/6J. Authors theorize that the observed increase in HDL cholesterol is most likely due to the Apoa2 locus. Since Tnfsf4 is outside the congenic region, Tnfsf4 and Apoa2 are most likely distinct and separate loci. Interestingly, the congenic exhibits increased aortic lesion development on a high fat diet compared to both donor strain BALB/cJ (atherosclerosis resistant) andbackground strain C57BL/6J (atherosclerosis susceptible).