Sequential chromosome banding and in situ hybridization analysis

Abstract

Different combinations of chromosome N- or C-banding with in situ hybridization (ISH) or genomic in situ hybridization (GISH) were sequentially 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 variation of the hot acid treatment in the standard chromosome N- or C-banding procedures was the major factor affecting the resolution of the subsequent ISH and GISH. By the sequential chromosome banding – ISH/GISH analysis, multicopy DNA sequences and the breakpoints of wheat–alien translocations were directly allocated to specific chromosomes of wheat. The sequential chromosome banding– ISH/GISH technique should be widely applicable in genome mapping, especially in cytogenetic and molecular mapping of heterochromatic and euchromatic regions of plant and animal chromosomes.Key words: N-banding, C-banding, in situ hybridization, genomic in situ hybridization.