玉米有丝分裂染色体上玉米BAC探针的FISH杂交体系的构建

本研究分别探讨了玉米和水稻基因组c 0t DNA对探针的封阻、杂交后洗脱的严谨度、杂交液中FAD的浓度变化对BAC-FISH杂交的影响；探讨了玉米BAC探针中重复序列含量对FISH信号的影响.初步形成了一套以玉米BAC探针在玉米有丝分裂染色体上进行FISH杂交的优化技术体系.结果表明,玉米基因组c 0t DNA对探针封阻的c 0t值应小于50；而降低杂交液中FAD浓度和适度控制杂交后洗脱的严谨度，尤其是使用水稻基因组的c 0t 100 DNA封阻探针重复序列对BAC-FISH杂交信号特异性的改善具有明显的效果；同时，验证了选择重复序列含量较少的玉米BAC作为FISH杂交的探针也是获得特异性杂交信号的重要条件.

Constructing FISH System with Maize BAC Probes on Mitotic Chromosomes of Maize

Fluorescence in situ hybridization(FISH)using the maize BAC-DNA as a probe had been performed on mitotic chromosomes.To optimize the BAC-FISH technique,we respective investigated signal specificities of FISH by analyzing the maize genomic c_0t DNA and rice genomic c_0t DNA blocking repetitive sequences of the probes-BAC,washing stringency after hybridization,FAD concentration in hybridization mixtures and containing repetitive sequence of the maize probes-BAC.The results showed that c_0t DNA of maize genomic blocked the repetitive sequence of the probes when the c_0t value was below 50.Meanwhiles,decreasing the FAD concentration in hybridization mixtures,adjusting the washing stringency after hybridization,especially blocking the repetitive sequences of maize probes-BAC with rice genomic c_0t-100 DNA which could improve the signals of BAC-FISH.The results demonstrated a important factor of receiving specific signals of BAC-FISH by select maize BAC-probes for lesser content repeat sequences.