Fecal samples were collected from individual mice of indicated strains at 4, 8 and 12 weeks of age and subjected to ELISA to determine dsDNA reactive IgA antibody titer as detailed under materials and method section. dsDNA reactive IgA titers per gram feces are shown. n= 14 males and 14 females for MRL/lpr, 15 males and 15 females for NZB/WF1, 10 males and 10 females for SNF1, 12 males and 12 females for NZM2410, and 10 males and 10 females for NZM2328 strains. P-value (by Mann-Whitney test) of male vs female comparisons are shown within the graph. P-values of other comparisons are shown on the right.