Mearow K M, Mill J F, Vitkovic L
Laboratory of Molecular Biology, NINDS, Bethesda, MD 20892.
Brain Res Mol Brain Res. 1989 Dec;6(4):223-32. doi: 10.1016/0169-328x(89)90068-5.
A 2.4 kb cDNA clone containing the coding sequence for glutamine synthetase (GS) was isolated from a rat brain cDNA library, and a probe constructed from this cDNA was utilized in Northern analysis of total RNA to study the tissue distribution and the ontogeny of GS mRNA expression in the rat brain from embryonic day 14 (E14) to adulthood. The levels of GS mRNA were highest in the brain, followed by kidney and liver. In the brain, the GS message was detected as early as E14, earlier than it can be detected by either enzymatic assays of GS activity or by immunocytochemical localization of GS. The relatively low levels of GS mRNA seen at E14 increase to a peak around the time of birth, and in the second postnatal week another rise in GS message occurs approaching adult levels by P15. Localization of GS to astrocytes in the brain was confirmed using both immunocytochemistry and in situ hybridization.
从大鼠脑cDNA文库中分离出一个包含谷氨酰胺合成酶（GS）编码序列的2.4 kb cDNA克隆，并利用该cDNA构建的探针进行总RNA的Northern分析，以研究大鼠脑从胚胎第14天（E14）到成年期GS mRNA表达的组织分布和个体发生。GS mRNA水平在脑中最高，其次是肾脏和肝脏。在脑中，早在E14就检测到GS信息，比通过GS活性酶促测定或GS免疫细胞化学定位检测到的时间更早。E14时GS mRNA相对较低的水平在出生时增加到峰值，在出生后第二周，GS信息再次升高，到出生后第15天接近成年水平。使用免疫细胞化学和原位杂交均证实了脑中GS定位于星形胶质细胞。
