Abstract
In addition to head-to-tail tandem repeats of injected pSV2-gpt-gE1A DNA, head-to-head and tail-to-tail tandem structures were detected in a transgenic mouse, pEl A/3, which showed the existence of inverted repeats. The injected DNA molecules in the founder mouse were segregated into two groups in its progeny. One group had about 80 copies of pSV2-gpt-gE1A and the other had 20 copies per diploid genome. Both the high and the low copy number lines contained inverted repeats. Breeding experiments showed that the inverted repeats in about half of the transgenic progeny were lost during the transmission from generation to generation. Progeny of the mice that lost the inverted repeats carried only head-to-tail tandem repeats.
Besides the inverted sequences, another portion of the transgene in the high copy line was found to be lost during germline transmission but independently.
