Mapping Data

Experiment

• Experiment
  TEXT-Congenic
• Chromosome
  13
• Reference
  J:161397 Shao H, et al., Analyzing complex traits with congenic strains. Mamm Genome. 2010 Jun;21(5-6):276-86
• ID
  MGI:5776495

Genes

Gene
Voq1
Bwvoq1

Notes

• Reference
  Sequential congenic segment analysis:
  
  The authors propose an alternative to 'common segment' congenic strain analysis to identify QTL. They have proposed calling the alternative method 'sequential' anaylsis. It is based on a unique principal of QTL analysis where each strain, corresponding to a single genotype, is tested individually for QTL effects rather than testing the congenic panel collectively for common effects across heterogeneous backgrounds.
  
  The sequential method is based on comparing phenotypes for sequential pairs of congenic strains, beginning with the strain with the shortest congenic segment and the host strain, and then in a stepwise fashion to strains with progressively longer, overlapping congenic segments. If the phenotypes for the strain with the shortest congenic segment and the host strain differ significantly, the conclusion is that at least one QTL maps to the congenic segment. Next, the congenic strain with the next longer, overlapping segment is compared to the previous congenic strain. If the introduced segment has a QTL the phenotypes for the first and second congenic strains will differ significantly, assigning a QTL to the chromosome segment that differs between the two strains. The process is repeated until each strain in the panel has been tested once and only once.
  
  A panel of 15 congenic strains was derived from the C57BL/6J-Chr6^A/J/NaJ chromosome substitution strain (CSS-A6);
  a panel of 9 congenic strains was derived from the C57BL/6J-Chr10^A/J/NaJ chromosome substitution strain (CSS-A10); and
  a panel of 7 congenic strains derived from C57BL/6J-Chr13^A/J/NaJ chromosome substitution strains (CSS-A13). Each panel collectively spans the length of the chromosome, and the congenic segments are bounded on one end by a telomere, except of 6C15 and 13C25 strains.
  
• Experiment
  The age (in days) at vaginal opening in pubertal females differed significantly for the CSS-A13 and C57BL/6J strains. The comparison between 13C25 (B6.A-(19.6-78 Mb)/13C25Na and C57Bl/6J provided a statistically significant result, suggesting that Voq1 (vaginal opening QTL 1), p=0.001, is located in the A/J derived interval distal to the marker at 78 Mb. [Comparison and p values Fig 1, F.]
  
  Another QTL Bwvoq1 (body weight at vagainal opening QTL 1) was identified in a significant comparison between 13C8 (B6.A-(118 Mb-tel)/13C8Na) and C57BL/6J females, mapping to the most telomeric interval distal to the marker at 118 Mb. [Comparison and p values Fig 1. G.]
  
  With these results the authors conclude that the sequential method performs better than the common-segment, interval mapping and multiple linear regression methods.