Transcriptional ontogeny of the developing liver

We characterized gene expression changes in the developing mouse liver at gestational days (GD) 11.5, 12.5, 13.5, 14.5, 16.5, and 19.5 and in the neonate (postnatal day (PND) 7 and 30) using full-genome microarrays and compared these changes to that in the adult liver. The fetal liver, and to a lesser extent the neonatal liver, exhibited dramatic differences in gene expression compared to adults. Canonical pathway analysis of the fetal liver signature demonstrated increases in functions important in cell replication and DNA fidelity whereas most metabolic pathways of intermediary metabolism were suppressed. Comparison of the dataset to a number of previously published datasets revealed 1) a striking similarity between the fetal liver and that of the pancreas in both mice and humans, 2) a nucleated erythrocyte signature in the fetus and 3) suppression of most xenobiotic metabolism genes throughout development, except a number of transporters associated with expression in hematopoietic cells. Keywords: gene expression/microarray We characterized gene expression changes in the developing mouse liver at gestational days (GD) 19 and in the neonate (postnatal day (PND) 7 and 30) using full-genome microarrays and compared these changes to that in the adult liver. Total RNA was isolated from liver samples and gene expression analyzed using Affymetrix Mouse 430 2.0 GeneChips. Data from 16 samples, with four mice in each of the four age groups, were analyzed.本研究通过全基因组微阵列（full-genome microarrays）分析了发育阶段小鼠肝脏在妊娠第11.5、12.5、13.5、14.5、16.5及19.5天，以及新生阶段（出生后第7天和第30天，postnatal day (PND) 7 and 30）的基因表达变化，并将其与成年小鼠肝脏的基因表达变化进行了对比。 与成年小鼠肝脏相比，胎肝以及在较小程度上新生鼠肝脏的基因表达均呈现出显著差异。 对胎肝特征基因集进行经典通路分析后发现，与细胞复制及DNA保真性相关的重要功能通路出现上调，而大多数中间代谢相关的代谢通路则被抑制。 将本数据集与多项已发表的数据集进行比对后发现：1) 小鼠和人类的胎肝与胰腺组织的基因表达模式存在显著相似性；2) 胎肝中存在有核红细胞特征基因集；3) 在整个发育阶段中，除部分与造血细胞表达相关的转运蛋白编码基因外，绝大多数外源性物质代谢基因均被抑制。 关键词：基因表达/微阵列 本研究通过全基因组微阵列分析了发育阶段小鼠肝脏在妊娠第19天以及新生阶段（出生后第7天和第30天）的基因表达变化，并将其与成年小鼠肝脏的基因表达变化进行了对比。 研究人员从肝脏样本中分离总RNA，采用Affymetrix Mouse 430 2.0基因芯片进行基因表达分析。 本研究共分析了16个样本，四个年龄组每组各包含4只小鼠。