Genome. 1994 Dec;37(6):1018-21. doi: 10.1139/g94-144.
This is the first report of fluorescence in situ hybridization (FISH) on plant polytene chromosomes. Different protease pretreatments have been tested to improve fluorescence in situ hybridization FISH on polytene chromosomes of a plant, Phaseolus coccineus, with the aim to enable the detection of low-copy genes. The structural preservation of the chromosomes and the distinctness of the FISH signals were comparatively analysed with a probe for the ribosomal RNA genes after digestion with pepsin and trypsin. The pepsin pretreatment resulted in a general loosening of chromatin with good conservation of chromosome morphology and an increased number and density of signal points. The six nucleolus organizers exhibited significant differences in condensation. The pretreatment with pepsin enabled the detection of the low-copy genes encoding the seed storage protein phaseolin.
这是荧光原位杂交（FISH）在植物多线染色体上应用的首次报道。为了能够检测低拷贝基因，我们测试了不同的蛋白酶预处理方法以提高植物多线染色体的荧光原位杂交 FISH 效果，所用植物为菜豆 Phaseolus coccineus。我们比较分析了胃蛋白酶和胰蛋白酶消化后，用核糖体 RNA 基因探针进行杂交的结果，以评估染色体结构的保存情况和 FISH 信号的清晰度。胃蛋白酶预处理导致染色质普遍松散，但染色体形态得到良好保存，信号点的数量和密度增加。六个核仁组织者在浓缩方面表现出显著差异。胃蛋白酶预处理可检测到编码种子贮藏蛋白菜豆球蛋白的低拷贝基因。
