SEQUENTIAL CHROMOSOME-BANDING AND IN-SITU HYBRIDIZATION ANALYSIS

Different combinations of chromosome N- or C-banding with in situ hybr idization (ISH) or genomic in situ hybridization (GISH) were sequentia lly performed on metaphase chromosomes of wheat. A modified N-banding- ISH/GISH sequential procedure gave best results. Similarly, a modified C-banding - ISH/GISH procedure also gave satisfactory results. The va riation of the hot acid treatment in the standard chromosome N- or C-b anding procedures was the major factor affecting the resolution of the subsequent ISH and GISH. By the sequential chromosome banding - ISH/G ISH analysis, multicopy DNA sequences and the breakpoints of wheat-ali en translocations were directly allocated to specific chromosomes of w heat. The sequential chromosome banding- ISH/GISH technique should be widely applicable in genome mapping, especially in cytogenetic and mol ecular mapping of heterochromatic and euchromatic regions of plant and animal chromosomes.