Poliard A, Feldmann G, Bernuau D
Laboratoire de Biologie Cellulaire, Faculté de Médecine Xavier Bichat, Paris, France.
Differentiation. 1988 Nov;39(1):59-65. doi: 10.1111/j.1432-0436.1988.tb00081.x.
We report the cellular localization of alpha-fetoprotein (AFP) and albumin (ALB) gene transcripts in rat kidney and brain as detected by in situ hybridization on tissue sections with [35S]-labelled alpha-fetoprotein and albumin cDNA probes. Both types of mRNA were present in distinct cell populations of the developing kidney and brain. In the kidney, both gene transcripts were distributed over all developing tubular cells in the 20-day-old fetus. During the first 3 weeks of life, a gradual decrease in the expression of AFP and ALB mRNA was apparent, the rate of decrease being greater on proximal tubules than on the other tubular cells. From the 4th week onwards, a weak signal for both mRNAs persisted in the majority of the tubular cells. In the brain, all neuronal cells expressed both genes. Transcript cellular distribution was mainly cytoplasmic during fetal and early postnatal life and became predominantly nuclear at 3, 4 and 5 weeks, suggesting that posttranscriptional mechanisms are involved in the control of AFP and ALB gene expression at these stages. In the adult brain no significant signal was recorded thereafter. Coexpression of AFP and ALB transcripts by specific cell types, together with their gradual disappearance concomitant with postnatal organ maturation, suggests a possible role for these proteins in terminal differentiation processes of tubular and neuronal cells.
我们报告了通过用[35S]标记的甲胎蛋白和白蛋白cDNA探针在组织切片上进行原位杂交检测到的大鼠肾脏和大脑中甲胎蛋白（AFP）和白蛋白（ALB）基因转录本的细胞定位。两种类型的mRNA都存在于发育中的肾脏和大脑的不同细胞群体中。在肾脏中，两种基因转录本分布于20日龄胎儿的所有发育中的肾小管细胞。在出生后的前三周，AFP和ALB mRNA的表达明显逐渐下降，近端小管的下降速度比其他肾小管细胞更快。从第四周开始，大多数肾小管细胞中两种mRNA的信号仍然微弱。在大脑中，所有神经元细胞都表达这两种基因。在胎儿期和出生后早期，转录本的细胞分布主要在细胞质中，在3、4和5周时主要变为细胞核，这表明转录后机制参与了这些阶段AFP和ALB基因表达的控制。此后在成人大脑中未记录到明显信号。特定细胞类型对AFP和ALB转录本的共表达，以及它们随着出生后器官成熟而逐渐消失，表明这些蛋白质在肾小管和神经元细胞的终末分化过程中可能发挥作用。
