New mutants and their chromosome assignment in the fly Megaselia scalaris.

We describe six new mutants, spontaneous or EMS-induced, and a previously isolated radiation-induced mutant of Megaselia scalaris Loew (Diptera, Phoridae). Five are eye-color mutants, one affects the segmentation of the abdomen, and one disturbs the regular form and arrangement of ommatidia in the compound eye. A complementation test exposed two pairs of alleles among the five eye-color mutants, leaving three different loci that affect eye pigmentation. Two of them influence the amount of xanthommatin synthesized, and one blocks the ommochrome pathway at the kynurenine step. We established chromosome assignment of the mutants by crossbreeding them with Y chromosome-autosome translocation strains.

E antigen in the serum of HBs antigen-positive patients on maintenance dialysis and after transplantation.

The 'e antigen' (eAg) is specifically associated with hepatitis B virus infections and appears to be a marker for the infectivity and a prognostic indicator of the chronicity of liver disease. Therefore we examined by immunodiffusion the presence of eAg in the seum of HBsAg-positive patients on maintenance dialysis. The dialysis patients had a significantly higher incidence of positive eAg compared with a group of unselected HBsAg-positive patients without renal failure. In most of the dialysis patients the microscopic findings in the liver revealed only 'minimal changes'. Three eAg-positive patients received a renal transplant. Afterwards they displayed an appreciably increased eAg-yield on immunodiffusion and histology revealed chronic persistent hepatitis. It is assumed therefore that the immunodeficiency of patients undergoing chronic haemodialysis is possibly a supporting factor in the synthesis of eAg, and will perhaps induce a more subscute and prolonged course of hepatitis. The synthesis of eAg after renal transplantation may be enhanced by the additional immunosuppressive therapy.