The construction of a fine molecular map for the activator locus of the mutator in rice.

构建了水稻中激活该突变体的slg基因的精细分子图谱。首先，利用农林水产省水稻基因组小组提供的YAC文库调查含有slg基因座的YAC克隆。其次，通过RFLP分析和限制性酶切标记基因组扫描（RLGS）技术，对与slg基因座紧密连锁的DNA标记进行了筛选。第三，以反转录转座子为探针，通过Southern-blot分析研究了slg基因座中是否存在反转录转座子样元件。对YAC克隆的调查表明，YAC克隆Y 4270含有与slg位点连锁的RFLP位点G33（重组值3%）。通过反向PCR扩增Y 4270基因的两端，并以此为探针进行Southern杂交分析，结果表明Y 4270基因的两端均与slg位点连锁。根据该结果，可以说两个YAC端部中的一个端部应该比G33更靠近。利用RLGS对金宝祖的原始品种和突变株系（slg同源）进行了比较。作为RLGS分析的结果，发现三个DNA点特异于Gimbozu或突变系。但未发现多态性的分离与slg位点的分离之间存在相关性。以反转录转座子Tos 17为探针，发现了与slg位点相关的DNA多态性。因此，需要明确上述DNA片段与slg基因座之间的重组值，以便利用更大的作图群体构建slg基因座的精细分子图谱。

The construction of a fine molecular map for slg locus that activates the mutator in rice was carried out. First, YAC clones containing slg locus was surveyed using the YAC library provided form the Rice Genome Team of the Ministry of Agricultural Forestry and Fishery. Second, DNA markers closely linked to slg locus were surveyed through a RFLP analysis and a Restriction Landmark Genomic Scanning (RLGS). Third, the existence of retro transposon-like elements in slg locus was surveyed through a Southern-blot analysis using retro transposons as DNA probes. The survey of YAC clones showed that a YAC clone Y4270 contained RFLP locus G33 linked with slg locus (recombination value 3%). Both ends of the Y4270 were amplified through inverse PCR,then a Southern-blot analysis was carried out using these amplified DNAs as the probes The experimental results showed that both ends of the Y4270 linked to slg locus. From this result, it could be said that one of the two YAC ends should be located much closer than G33. With the use of the RLGS,the comparison was made between the original variety of Gimbozu and the mutant line (homogeneous for slg). As a result of the RLGS analysis, three DNA spots were found specific to either Gimbozu or the mutant line. However, no relation was found between the segregation of the polymorphism and the segregation of slg locus. DNA polymorphism related with slg locus was found when Tos17, one of the retro transposon, was used as the probe. Consequently, the accurate recombination values between above DNA segments and slg locus should be clarified to construct the fine molecular map for slg locus with the use of much larger mapping population.