Mapping Data

Experiment

• Experiment
  TEXT-QTL
• Chromosome
  1
• Reference
  J:97669 Namiki Y, et al., Quantitative trait loci analysis of heat stress resistance of spermatocytes in the MRL/MpJ mouse. Mamm Genome. 2005 Feb;16(2):96-102
• ID
  MGI:3579344

Genes

Gene	Assay Type
Sphsr1	visible phenotype
D1Mit403	PCR
Exo1	reported elsewhere

Notes

• Experiment
  Male animals from inbred strain MRL/MpJSlc exhibit heat stress-resistant spermatocytes. To map genetic loci associated with this phenotype, linkage analysis was performed on 140 male animals from a (C57BL/6CrSlc x MRL/MpJSlc)F2 intercross. 98 microsatellite markers at an average spacing of 10-20 cM were used for the genome scan. To expose spermatocytes to abdominal heat, unilateral experimental cryptorchidism was induced in male animals by surgery. Three weeks after surgery parental strain C57BL/6CrSlc displayed germ cell loss and reduced Sertoli cell index compared to MRL/MpJSlc males.
  
  A locus on mouse Chromosome 1 near D1Mit403 (100 cM) showed significant linkage to testis weight ratio (LOD=13.08) and Sertoli cell index (LOD=8.3). This locus is named Sphsr1 (spermatocyte heat stress resistance 1). A strong candidate gene for Sphsr1 is Exo1 at 97 cM. A mutation in Exo1 in MRL/MpJ animals has previously been shown to be involved in spermatocyte heat stress resistance.
  
  A locus on mouse Chromosome 11 near D11Mit5 (37 cM) showed significant linkage to testis weight ratio (LOD=2.8). This locus is named Sphsr2 (spermatocyte heat stress resistance 2).
  
  Suggestive linkage to testis weight ratio mapped to mouse Chromosomes 2 (D2Mit107; 75.6 cM), 4 (D4Mit235;1.9 cM), 7 (D7Mit178; 0.5 cM), 9 (D9Mit181; 48 cM), 11 (D11Mit212; 50 cM), and 15 (D15Mit245; 58.9 cM). Suggestive linkage to Sertoli cell index mapped to mouse Chromosomes 4 (D4Mit235; 1.9 cM) and 8 (D8Mit50; 41 cM).