GENOME PHYSICAL MAP OF DROSOPHILA

最初的果蝇基因组中心拨款建议建立一个基于克隆的 果蝇常染色质基因组的物理图谱 噬菌体P1文库和依赖于 STS内容映射。构建这张地图的主要动机是 为LBL的定向基因组测序项目提供良好的- 用于生成测序模板的特色化克隆。冲向 为了实现这一目标，我们在LBL建立了生产STS映射工作 每月能够为物理地图分配100个以上的STS标记。 该项目的STS标记的主要来源来自插入 原位定位于基因组中的P1克隆的末端 与多线染色体杂交。STS标记的其他来源是 用于这个项目的是已知的果蝇基因和被拯救的质粒 来源于致命的P元素注入。截至1994年7月31日，我们有 共定位了来自三个类别的1848个STS标记：P1末端序列， 拯救了P元素，以及已知的果蝇基因。总共有1299个这样的 STS标记来源于P1末端序列。这些STS标记加在一起有 将库中超过50%的克隆分配给重叠群，这些 重叠群覆盖了约70%的常染色质。在最初的 授权期(1995年7月31日)我们有信心90%-95%的常色度 基因组将以P1重叠群的形式出现。赠款的这一部分 提案是对这项工作的更新，并描述了我们绘制地图的方法 完成和重叠群闭合。本节中提出的实验 被组织成三个连续的阶段。首先，剩余的P1克隆 在当前生产STS映射阶段耗尽电流供应之后 用于产生末端STS标记的原位定位的P1克隆将 通过额外的STS映射实验进行分配。在所有的克隆人之后 文库已被分配到重叠群，即第二级实验 本节中提出的建议旨在缩小重叠群之间的明显差距 通过额外的STS作图实验。地图制作的最后阶段 将努力填补在主PI库中没有出现的差距。 缩小这些统计差距将通过筛选其他 提供上述另外7至8个基因组等价物的P1克隆 超出了主图书馆提供的覆盖范围。克隆以填补空白 这些实验后的剩余部分将通过筛选文库进行搜索 与其他载体系统一起构建，如lambda、COSMID和YAC。

The initial Drosophila Genome Center grant proposed to build a clone-based physical map of the Drosophila melanogaster euchromatic genome using a bacteriophage P1 library and a non-random mapping strategy that relied on STS content mapping. The major motivation for constructing this map is to provide the directed genomic sequencing project at LBL with well- characterized clones from which to generate sequencing templates. Toward this goal we have established a production STS mapping effort at LBL capable of assigning more 100 STS markers per month to the physical map. The major source of STS markers for this project derive from the insert ends of P1 clones that have been positioned in the genome by in situ hybridization to polytene chromosomes. Other sources of STS markers being used for this project are known Drosophila genes and rescued plasmids derived from lethal P element insertions. As of 31 July 1994 we have mapped a total of 1848 STS markers from three classes: P1 end sequences, rescued P elements, and known Drosophila genes. A total of 1299 of these STS markers derive from P1 end sequences. Together these STS markers have assigned over 50% of the clones in the library to contigs, and these contigs cover about 70% of the euchromatin. At the end of the initial grant period (31 July 1995) we are confident that 90-95% of the euchromatic genome will be represented in P1 contigs. This section of the grant proposal is a renewal of this work and describes our approaches to map completion and contig closure. The experiments proposed in this section are organized in three sequential stages. First, the P1 clones remaining after the current production STS mapping phase exhausts the current supply of in situ localized P1 clones used to generate terminal STS markers will be assigned by additional STS mapping experiments. After all the clones in the library have been assigned to contigs, the second level of experiments proposed in this section are aimed at closing apparent gaps between contigs by additional STS mapping experiments. The final stage of map completion will be efforts to close gaps not represented in the master PI library. Closing these statistical gaps will be accomplished by screening additional P1 clones that provide another seven to eight genomic equivalents above and beyond the coverage provided by the master library. Clones to fill gaps remaining after these experiments will be sought by screening libraries constructed with other vector systems such as lambda, cosmid, and YAC.