Cytoplasmic requirement for peroxisome biogenesis in Chinese hamster ovary cells.
Hybrids constructed by fusion of wild-type Chinese hamster ovary cells (CHO-K1) to peroxisome-deficient CHO mutants (ZR-78.1) contain normal peroxisomes, demonstrating that the mutation(s) are recessive. "Nuclear hybrids" prepared by fusion of CHO-K1 karyoplasts to mutant ZR-78.1 occasionally fail to regain intact peroxisomes (approximately 1/300 cells). These peroxisome-deficient nuclear hybrids closely resemble the original mutant cells by biochemical criteria, but their modal chromosome number is 36-38, the same as that of CHO hybrids generated from intact cells. When the peroxisome-deficient nuclear hybrids are fused to wild-type cytoplasts, a fraction of the fusion products (at least 70%) continue to propagate normal peroxisomes indefinitely. Peroxisome biogenesis cannot be reinitiated in cells of mutant ZR-78.1 by fusion to wild-type cytoplasts. Our results suggest that a wild-type nucleus by itself is necessary but not sufficient for restoration of normal peroxisome biogenesis and that a cytoplasmic component of wild-type cells, possibly a normal peroxisome, is also required.
Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin, Madison 53706.
L A
LA
Allen
O H
OH
Morand
C R
CR
Raetz
D000818:Animals; D002459:Cell Fusion; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D003593:Cytoplasm / Q000502:physiology; D005260:Female; D006822:Hybrid Cells / Q000166:cytology / Q000502:physiology; D008830:Microbodies / Q000502:physiology* / Q000648:ultrastructure; D009154:Mutation; D010053:Ovary; D010955:Plasmalogens / Q000032:analysis
D010955:Plasmalogens