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：1990
卷号：87
期号：5
页码：1758-1761
DOI：10.1073/pnas.87.5.1758
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We have recovered terminal chromosome deletions of the X chromosome of Drosophila [Df(1)RT; RT = receding tips] that break in various positions of the yellow gene (y) region and delete all distal DNA sequences. Terminal DNA fragments are heterogeneous in length. Molecular cloning and sequencing of the terminal DNA fragments revealed that the broken ends of the deleted chromosomes do not carry any telomeric DNA sequences, yet the broken chromatids do not fuse to one another. Moreover, we confirmed by sequence analysis of 49 independently cloned terminal DNA fragments from two RT lines collected at different times that they lose DNA sequences from their distal ends at a rate of 70-75 base pairs per fly generation. We calculate that the rate of loss from these ends is consistent with the removal of an octanucleotide RNA primer at each round of DNA replication in the germ line.
