Transformation does not select pre-existing structures but creates <i>de novo</i> merodiploids.

<p>(A) Detection of tandem-duplication junction by PCR on cultures at different time points after transformation with R-NRf fragments alone. (B) Detection of abortive chromosome junction on same transformed cultures as in panel A. (C) Detection of tandem-duplication and abortive chromosome junctions by PCR on cultures at different time points after self-transformation. (D) Integration of donor R₁*-A fragment during merodiploid formation. Right panel shows <i>Bam</i>HI restriction of TD junction PCRs recovered from Trim^R clones transformed with <i>codY</i>::<i>trim</i> and R₁*-A PCR fragments. Undigested PCR shown in green, products of <i>Bam</i>HI digestion shown in orange. Left panel shows <i>Bam</i>HI digestion of TD junction PCR amplified from population transformed with R₁-A or R₁*-A. −, undigested PCR fragment; +, <i>Bam</i>HI-digested PCR fragment.