Complexity and application of pedigree analysis programme GTree

A novel recombinant congenic mouse strain, McRA1lpr/lpr, which was established by the intercrosses between MRL/Mp/-lpr/lpr and C3H/HeJ-lpr/lpr strains throughout more than F50 generations by means of selection based on swelling of ankle joints, manifested severe arthritis, followed by ankylosis, pathologically resembling rheumatoid arthritis in humans. To clarify the genetic mechanisms on the development of arthritis in this strain, we newly prepared "GTree" for analyzing the pedigree of pathological phenotypes of arthritis, splenomegaly and lymphadenopathy based on the collected data from over 700 McRA1-lpr/lpr mice collected and arranged by Shiro MORI. The data themselves are now dealt with by a PostgreSQL Linux server administered by Hideki SAWADA. We explain the algorithm of the program and its complexity, and show the pathological peculiarity of spleens and axillary lymph nodes which appear only in the group of RA mice.