This allele is a polymorphism resulting in a protein of slow electrophoretic ability compared to C3a (intermediate) and C3c (fast). C57BL/6 and most other strains carry this allele including BALB/c, C57BL/6J, AKR, CBA/J, DBA/1 and DBA/2.
Legend:
cx: complex: > 1 genome feature ot: other: hemizygous, indeterminate,... (F): Female
(M): Male
N: normal phenotype
(#): related diseases count