Temporal changes of gene expression in rat kidney and lung, and the effect of prior growth inhibition on these changes. Rattus norvegicus

Temporal changes of gene expression from 1-wk- to 5-wk-old rat in kidney and lung, and the effect of prior growth inhibition on these genetic changes. In mammals, body growth is rapid in early life but decelerates with age. Somatic growth deceleration is caused by a gradual decline in cell proliferation that occurs simultaneously in many different organs, but is not caused by a hormonal mechanism. We hypothesize that growth deceleration is driven by a postnatal genetic program that occurs coordinately in multiple organs. Using microarrays, we investigated the changes of gene expression that occur with age in kidney and lung as growth slows down, and also investigated whether these changes were growth-driven, by asking whether prior delay of postnatal growth caused by malnutrition (tryptophan deficiency) would also delay these genetic changes. Overall design: To compare gene expression between fast-growing animals and more slowly growing animals, we extracted total mRNA from kidney and lung in 1-wk-old and 5-wk-old mice (5 animals each). Then, to investigate the effect of prior growth on these genetic changes, we also extracted total mRNA from kidney and lung in 5-wk-old mice that received a tryptophan-deficient diet from birth to 4wk of age.

本数据集聚焦1周至5周龄大鼠肾脏与肺部的基因表达时序变化，以及既往生长抑制对这类遗传表达改变的影响。
在哺乳动物中，个体出生后的早期生长速度较快，但随年龄增长逐渐放缓。体细胞生长减速源于多器官同步发生的细胞增殖能力逐步下降，而非激素调控机制所致。本研究提出假说：生长减速由多器官协同激活的出生后遗传程序驱动。通过基因芯片（microarrays）技术，我们探究了随生长放缓的年龄进程中，肾脏与肺部的基因表达变化；同时通过构建营养不良（tryptophan deficiency）诱发的出生后生长延迟模型，验证此类基因表达改变是否由生长进程驱动。
整体实验设计：为比较快速生长与慢速生长动物的基因表达差异，我们分别从1周龄和5周龄小鼠（每组各5只）的肾脏与肺部提取总mRNA（total mRNA）。此外，为探究既往生长对上述遗传表达改变的影响，我们还从出生至4周龄期间饲喂色氨酸缺乏日粮（tryptophan-deficient diet）的5周龄小鼠的肾脏与肺部提取总mRNA（total mRNA）。