Abstract
The kidneys of a group of tetraparental AKR↔CBA/H-T6 mouse chimaeras derived by early embryo aggregation showed minimal evidence of immune complex glomerulonephritis when examined by light and electron microscopy. Significant abnormalities comparable with those found in the parental AKR strain were seen only in two of those animals which had developed lymphomas. The results support the earlier conclusion from immunofluorescence microscopy and renal elution studies that the lack of anti-Gross virus antibody activity in the chimaeras is responsible for preventing or delaying the development of both renal and lymphomatous disease in these animals.