Cytoplasmic Requirement for Peroxisome Biogenesis in Chinese Hamster Ovary Cells

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 86; no. 18; pp. 7012 - 7016
• Main Authors: Allen, Lee-Ann H., Morand, Olivier H., Christian R. H. Raetz
• Format: Journal Article
• Language: English
• Published: Washington, DC National Academy of Sciences of the United States of America 01.09.1989; National Acad Sciences
• Subjects: Animal cells; Animals; Biological and medical sciences; Cell cultures. Hybridization. Fusion; Cell Fusion; Cell growth; Cell Line; Cell lines; Cell nucleus; Cells; CHO cells; Cricetinae; Cricetulus; Cytoplasm - physiology; Female; Fundamental and applied biological sciences. Psychology; Hybrid Cells - cytology; Hybrid Cells - physiology; Hybridity; Microbodies - physiology; Microbodies - ultrastructure; Molecular and cellular biology; Mutation; Ovary; Peroxisomes; Plasmalogens - analysis; Somatic cells; Autoradiography; Density gradient centrifugation; Cell culture; Hybrid cell; Radiolabelling; Peroxisome; Biosynthesis; CHO cell line; Ultraviolet visible spectrometry
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.86.18.7012

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 (≈ 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.