Okubo K, Itoh K, Fukushima A, Yoshii J, Matsubara K
Institute for Molecular and Cellular Biology, Osaka University, Japan.
Genomics. 1995 Nov 20;30(2):178-86. doi: 10.1006/geno.1995.9887.
A gene expression profile is the list showing the expressed gene species and the abundance of their transcripts in a given cell or tissue. This list is made by constructing 3'-directed cDNA libraries consisting of only the 3'-termini of mRNA and sequencing randomly selected clones from such libraries: genes are identified by the sequences, and the composition of mRNA, which reflects gene activities, is measured from the frequency of appearance of the gene transcripts. For practical reasons, the number of sequenced clones has been limited to approximately 1000 per library at present, but the resulting profile covers almost all highly or moderately expressed genes, along with many less active genes. We constructed expression profiles from the HL60 human promyelocytic cell line and two of its derivatives, granulocytoids induced by DMSO and monocytoids induced by TPA. In HL60, a significant fraction of the abundantly expressed genes was for protein synthesis. Upon induction, these genes were partially or totally silenced; transcripts for proteins that characterize the granulocytes and monocyte-macrophages became abundant. By compiling and comparing different expression profiles, genes can be categorized into those expressed in diverse cell types and those active only in limited cell types. Although at present, the number of expression profiles that can be compiled is limited and this categorization is applicable only to abundantly expressed genes, 13 novel genes that may represent granulocyte- or monocyte-specific functions have been discovered.
基因表达谱是一份清单，展示了给定细胞或组织中表达的基因种类及其转录本的丰度。这份清单是通过构建仅由mRNA的3'末端组成的3'定向cDNA文库，并对这些文库中随机选择的克隆进行测序来生成的：通过序列鉴定基因，并根据基因转录本出现的频率来测量反映基因活性的mRNA组成。出于实际原因，目前每个文库测序的克隆数量限制在大约1000个，但由此产生的表达谱涵盖了几乎所有高表达或中等表达的基因，以及许多活性较低的基因。我们构建了来自HL60人早幼粒细胞系及其两个衍生物的表达谱，这两个衍生物分别是由二甲基亚砜诱导的粒细胞样细胞和由佛波酯诱导的单核细胞样细胞。在HL60中，大量表达的基因中有很大一部分是用于蛋白质合成的。诱导后，这些基因部分或完全沉默；表征粒细胞和单核细胞-巨噬细胞的蛋白质的转录本变得丰富。通过汇编和比较不同的表达谱，可以将基因分类为在不同细胞类型中表达的基因和仅在有限细胞类型中活跃的基因。虽然目前可以汇编的表达谱数量有限，而且这种分类仅适用于高表达基因，但已经发现了13个可能代表粒细胞或单核细胞特异性功能的新基因。
