Molecular verification of chromosomal rearrangements. (A) Scheme of a chromosome before and after inversion. (B) Molecular verification of chromosomal inversions by genomic Southern-blotting with SalI and BamHI digested DNA. The Southern probe detects the EGFP sequence in DE16. The size of the SalI fragment is dependent on the chromosomal insertion site of the P-element DE20, whereas the BamHI fragment is independent of the genomic context of DE20 because both BamHI sites are located within the P-element. Arrows mark bands characteristic for an inversion, and arrowheads mark bands representing the original construct. Numbers above the lanes denote arbitrary isolate numbers: The first number denotes flies from different tubes and thus different events, and the second number represents the number of an individual fly taken from a particular tube. The lines from which the events are derived are indicated in parentheses above the lanes: α, DE16d*-DE20z; β, DE16c-DE20h; and γ, DE16c-DE20y. The latter two share the same DE16 starter P-element insertion. Lowercase letters arbitrarily denote the isolated P-element insertion. (C) Scheme of a chromosome 2 (left) and chromosome 3 (right) before the translocation and of the rearranged chromosomes. Small arrows indicate primers for the verification of the translocation. (D) PCR of three different translocation events (1–3) and of the δϵ starter strain.
