Supplementary Figure 1. Genetic architecture of nephrotoxic nephritis.

Segregation of (a) crescent scores, (b) proteinuria and (c) glomerular macrophage infiltration in Lewis and WKY parental strains, and in F1 and F2 animals. (GCS – glomerular cross section).

Supplementary Figure 2.Fcgr3 clonotypes in Lewis, WKY and Brown Norway rats.

Exon 5 sequences derived from multiple sources were aligned using ClustalW (manual adjustments were made using BioEdit). All consensus columns in the multiple alignment were deleted, leaving sequences at variant positions only. The reduced sets of sequences were compared and all identical sequences, or ‘clonotypes’, were grouped together and assigned a letter. Yellow highlighting indicates sequence variants unique to WKY; blue highlighting indicates sequence variants unique to Lewis or Brown Norway. Dashes denote missing sequence. "D" denotes a deleted nucleotide. Nucleotide numbering is from the start of exon 5 according to the ENSEMBL annotation, ENSRNOG00000003138. * This denotes loss of the SINE element from nucleotides 337-562. ** The BN sequences were obtained from the rat genome sequence at

Supplementary Figure 3. Surface expression of transfected Fcgr3 isoforms

(a) Representative FACS data. The flow cytometry is presented as scattergrams of forward-scatter (FSC-H) versus fluorescence (FITC). The upper left panel defines background expression and shows cells stained with isotype control antibody. The other panels show cells transfected with myc-tagged Fcgr3 constructs and stained with anti-myc antibody. (b) Percentage of transfectants detectably expressing surface receptors. This was the proportion of unpermeabilised cells falling within the flow cytometry gate set as in Panel A. Each bar represents mean  S.E.M. for n=5 transfectants. There is no statistical difference between constructs (P>0.05, Student’s t-test). (c) Level of surface expression of the positively expressing cells. The level of expression was analysed after gating for backgound cells (Panel A). Respective constructs are indicated in the Figure. There is no difference in level of surface expression.

Supplementary Figure 4. Gene copy number quantification for CD36 and FCGR3B.

Box and whisker graphs indicate the median, first and third quartiles, and 1.5 times the inter-quartile range of gene copy number for the CD36 and FCGR3B genes estimated by quantitative PCR.