期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1972
卷号：69
期号：9
页码：2410-2413
DOI：10.1073/pnas.69.9.2410
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The mechanism of preferential transmission (i.e., maternal inheritance) of cytoplasmic genes was investigated with chloroplast DNA of Chlamydomonas as a model system. The behavior of nuclear and chloroplast DNAs were compared in the sexual cycle; DNAs from male and female parents were distinguished by labeling with 14N- or 15NH4Cl and then by making the crosses: 14N (female) x 15N (male) and the reciprocal. Chloroplast DNAs from the two parents followed different paths in the zygote, but nuclear DNAs showed no differences. Chloroplast DNA from the female parent persists in the zygote, but undergoes a density shift of 0.003-0.005 g/cm3 to a lighter buoyant density, whereas that from the male disappears soon after zygote formation. The possibility is discussed that a modification-restriction system may be involved.
关键词：cytoplasmic genes ; chloroplast DNA ; cesium chloride density gradients ; 15N density label ; Chlamydomonas
