SP5
Generation of novel subcongenic BXSB mouse models to investigate the role of
the HIN200 gene family in the development of Systemic Lupus Erythematosus
Allyson Egan1, Jane Rose1, Michael Jones2 Department of Medicine1, Genomics Laboratory, MRC Clinical
Sciences Centre2 Hammersmith Hospital, Imperial College London
Introduction
Systemic Lupus Erythematosus (SLE) is likely to represent an interplay between inherited genetic
susceptibility and exposure to environmental triggers. Lupus prone mouse model BXSB develops
autoantibodies, nephritis and accelerated mortality1. The telomeric region of chromosome 1, and a syntenic
region in humans, has been implicated in the development of SLE. This interval carries three candidate gene
families – HIN200, Slam and Fcgamma. HIN200, an interferon response gene family, contains a HIN-200
amino acid region which binds to DNA and a pyrin domain which homo/ oligodimerises. Aim2 is a newly
identified cytosolic DNA sensor which triggers the inflammasome with activation of caspase-1 and production
of Il-18 and Il-1β2. This project aims to generate a novel subcongenic murine model containing the HIN200
gene family in order to investigate HIN200’s contribution to the SLE phenotype.
Methods
To achieve recombination between the Ifi200 cluster and the Slam/Fcgamma gene families (B10 x
B10.Yaa.Bxs3)F1 male mice were backcrossed to female B10, hence maintaining the Y chromosome from the
male congenic. C1 is 200Mb in length There is a 2Mb distance between the Ifi200 and Slam (Ly108,
173.7Mb) gene clusters which represents a region of approximately 1% recombination (1/100 crosses).
Offspring were genotyped by polymerase chain reaction using microsatellite markers D1Mit33, D1Mit 36,
DiMit355, D1Mit 403 and D1Mit 223 along with previously identified primers for a microdeletion in the
Fcgr2 locus. Sequencing was performed in the Slam locus with known SNPs in genes Nit (3), Ncstn (4) and
Cd229 (6).
Results
Recombination occurred to produce four mice with recombination between satellite markers D1Mit 355 and
D1Mit36. Genotyping the Fcgr locus identified two B10 and two heterozygous offspring at this locus.
Sequencing at the Slam locus identified that of the two mice that were B10 at Fcgr locus one was
heterozygous generating B10.Yaa.Bxs3.Ifi. The second recombinant was heterozygote at the Slam locus
generating B10.Yaa.IfiSlam. For the two heterozygote mice at the Fcgr locus, one was B10 at the Slam locus
generating B10.Yaa.Bxs3. Fcgr. The second was
heterozygote at the Slam locus generating
B10.Yaa.Bxs3.Fcgr/Slam. To secure the lines these four novel heterozygote offspring were crossed and
genotyped for a further three backcrosses with the aim of producing homozygotes.at the regions of interest.
This was achieved to generate novel subcongenics B10.Yaa.Bxs3.Ifi, B10.Yaa.Ifi/Slam and
B10.Yaa.Bxs3.Fcgr.
Conclusion
Generation of the three novel subcongenics B10.Yaa.Bxs3.Ifi, B10.Yaa.Bxs3.Ifi/Slam and B10.Yaa.Bxs3.Fcgr
uniquely facilitates dissection of the candidate gene families HIN200, Slam and Fcgramma’s contribution to
the SLE phenotype. Regional epistasis can be explored using the additional strains and the bicongenic
B10.Yaa.Bxs3.Ifi/Slam.
References
1. Morley et al. JI 2004, 173:4277-4285. 2. Burckstummer et al Nature Immunology vol 10, Number 3 March 2009