Mapping and Gene Content of the Mouse t-complex

小鼠17号染色体上的t复合体一直是发育生物学家关注的焦点。由于许多胚胎致死突变位于该区域，因此推断发育中重要的相应基因位于该区域，因此它是高优先级序列分析的主要目标。我们的合作者的发现，该地区包含大量的其他未知的基因，包括许多选择性表达的外胎盘锥，既强调了该地区的重要性，并提供探针，以筛选底物的远程序列分析。因此，我们已经开始绘制和分析t-复合体的一个数百万的部分.从最初靶向的10 Mb重叠测序的标记位点/细菌人工染色体（BAC）物理图谱中，已完成1.282 Mb BAC克隆的测序，准确度大于99.9%。测序区域的GC含量从40%到高达50%不等，相应的基因浓度范围。我们的序列分析的主要工具是与Genbank EST数据库，外显子预测程序GRAIL，重复序列发现程序CENSOR进行比较，并使用CpG含量作为CpG岛和基因的测定。到目前为止，BAC 126 c8的完整注释已经鉴定了11个基因，其中5个是已知基因。 它们是Rsp 29、Als、Nubp 3、Jsap 1和Ndk 3。剩下的6个预测基因是新的。 对另外6种BAC的初步序列分析已经确定了Rsk 3、基质溶解素、氯通道7、泛素结合酶和Pdpk 1的片段形式的基因;以及一组含锌指蛋白的基因，包括ZNF 54、ZFP 51和Zfp 118以及另外一个先前未检测到的ZNF家族成员。目前，另一个2 Mb的测序正在进行中，靶向包括几个胚胎致死基因座的区域。

The mouse t-complex on chromosome 17 has long been a focus of interest for developmental biologists. Because many embryonic lethal mutations are localized in the region, and corresponding genes of importance in development are therefore inferred to reside there, it is a prime target for high priority sequence analysis. The findings of our collaborators that the region contains a large number of otherwise unknown genes, including many expressed selectively in the ectoplacental cone, both underlines the importance of the region and provides probes to screen for substrates for long-range sequence analysis. We have thus started to map and analyze a multimegabase portion of the t- complex. From the initially targeted 10 Mb of overlapping sequenced tagged site/bacterial artificial chromosomes (BACs) physical map , the sequencing of 1.282 Mb of BAC clones has been completed with greater than 99.9% accuracy. The GC content of the sequenced region varies from 40% to a high of 50%, with a corresponding range of gene concentations.Our main tools for sequence analysis are comparison with the Genbank EST database, the exon-predicting program GRAIL, the repetitive sequence-finding program CENSOR, and the use of CpG content as an assay for CpG islands and genes. Thus far, complete annotation of one BAC 126c8 has identified 11 genes of which 5 are known genes. They are Rsp29, Als, Nubp3, Jsap1, and Ndk3. The remaining 6 predicted genes are new. Preliminary sequence analysis of the 6 additional BACs has identified genes for a fragmentary version of Rsk3, Stromelysin, Chloride channnel 7, Ubiquitin conjugating enzyme, and Pdpk1; and for a cluster of Zinc Finger-containing proteins that include ZNF54, ZFP51, and Zfp118 as well as an additional previously-undetected ZNF family member. Currently another 2 Mb of sequencing is in progress, targeting regions that include several embryonic lethal loci.