The improved "bithorax method" for the detection of rearrangements in Drosophila melanogaster.

For the improved "bithorax method", homozygous ss sbd2 bx34e females and D3 Ubx e4/Payne ca males were used. The factor Dichaete (D3) permits easier scoring of the transvection phenotype. The female stock used is not deficient in the maternal repair system and therefore gave high yields of rearrangements. Furthermore--compared with that used before--the stock is more viable and more reproductive. To test the method, males were irradiated with X-rays or treated with the chemical mutagens diepoxybutane (DEB) or diethylnitrosamine (DEN). The frequencies of rearrangements recovered are comparable to those obtained with the conventional translocation tests.