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：1978
卷号：75
期号：5
页码：2368-2372
DOI：10.1073/pnas.75.5.2368
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：In the mouse strain GR, the Mtv-2 gene controls the expression of large amounts of mammary tumor virus (MTV) antigens in the milk at first lactation. It also controls the early appearance of mammary tumors. We have investigated the number of MTV proviral sequences associated with this Mtv-2 gene by nucleic acid hybridization between MTV [3H]cDNA and DNA from GR, B10, and GR-Mtv-2- mice. B10 and GR-Mtv-2- mice lack Mtv-2 gene expression. The molecular hybridizations revealed that the DNA of GR mice contains 12 copies of MTV proviral sequences, whereas only 4 copies are present in the DNA of B10 and GR-Mtv-2- mice. We therefore conclude that the Mtv-2 gene in the GR mouse strain is associated with eight additional MTV proviral sequences. The four Mtv proviral sequences in the GR-Mtv-2- DNA might represent another Mtv gene in the GR mouse. Different amounts of MTV RNA are detected in mammary glands at first lactation of B10 and GR-Mtv-2- mice, even though both contain four copies of MTV proviral sequences. This indicates a difference between these two mouse strains either in the regulation of expression of these MTV proviral sequences or in the location of these sequences in the murine genome.
关键词：mammary tumor virus DNA sequences ; DNA and RNA annealing kinetics ; congenic mouse strain
