Chromosome 22

A DNA microarray representing nearly all of the unique sequences of human Chromosome 22 was constructed and used to measure global-transcriptional activity in placental poly(A)(+) RNA. We found that many of the known, related and predicted genes are expressed. More importantly, our study reveals twice as many transcribed bases as have been reported previously. Many of the newly discovered expressed fragments were verified by RNA blot analysis and a novel technique called differential hybridization mapping (DHM). Interestingly, a significant fraction of these novel fragments are expressed antisense to previously annotated introns. The coding potential of these novel expressed regions is supported by their sequence conservation in the mouse genome. This study has greatly increased our understanding of the biological information encoded on a human chromosome.本研究构建了一套覆盖人类22号染色体几乎全部独特序列的DNA微阵列（DNA microarray），并利用其对胎盘poly(A)阳性RNA的全局转录活性进行检测。研究发现，大量已知、相关及预测的基因均存在表达现象。更为重要的是，本研究检测到的转录碱基总量为既往报道的两倍。多数新发现的表达片段通过RNA印迹分析与一种名为差异杂交作图（differential hybridization mapping, DHM）的新型技术得到验证。值得注意的是，这类新发现的表达片段中有相当一部分与既往已注释的内含子呈反义表达。这些新发现的表达区域的编码潜力，可通过其在小鼠基因组中的序列保守性得到佐证。本研究极大地深化了我们对人类染色体所编码的生物学信息的认知。

搜集汇总

背景与挑战

背景概述

该数据集基于人类22号染色体的DNA微阵列研究，测量了胎盘poly(A)(+) RNA的全局转录活性，发现转录碱基数量是之前报道的两倍。新发现的表达片段通过RNA印迹分析和差异杂交定位验证，部分以反义方式表达于内含子，其编码潜力得到小鼠基因组序列保守性支持。这项研究显著增进了对人类染色体生物信息的理解。