Dkhissi O, Julien J F, Wasowicz M, Dalil-Thiney N, Nguyen-Legros J, Versaux-Botteri C
Laboratoire Cerveau et Vision, INSERM U371, Lyon, France.
Brain Res. 2001 Nov 23;919(2):242-9. doi: 10.1016/s0006-8993(01)03022-0.
The development of synthetic enzymes in the GABAergic system (GAD(67) and GAD(65)) of the rat retina was analyzed from birth to the 4th postnatal week by the reverse transcriptase polymerase chain reaction (RT-PCR) and by immunohistochemistry. As previously observed for GABA, immunoreactive GAD(67) profiles are seen clearly in the inner retinal layers at birth. At the end of the 1st week of postnatal life, immunolabeling is detected in amacrine and/or ganglion cells and in horizontal cells. GAD(67) immunoreactivity is transiently expressed in horizontal cells and disappears during the 3rd postnatal week. GAD(65) however does not develop until the 5th postnatal day. Immunolabeling is detected in the processes layering the inner plexiform layer (IPL) before being detected in the amacrine and/or ganglion cell bodies. The appearance of transcripts for GAD coincided with the appearance of the proteins. A transient form of mRNA transcripts of the GAD(67) gene containing an extra exon (ES-exon) is also observed which disappears progressively from birth to the 4th postnatal week. This form synthesizes a truncated, enzymatically inactive protein, which could participate in the regulation of GABA synthesis from glutamate present at high levels during retinogenesis.
通过逆转录聚合酶链反应（RT-PCR）和免疫组织化学方法，分析了从出生到出生后第4周大鼠视网膜GABA能系统（GAD(67)和GAD(65)）中合成酶的发育情况。如先前对GABA的观察，出生时在视网膜内层可清晰看到免疫反应性GAD(67)轮廓。在出生后第1周结束时，在无长突细胞和/或神经节细胞以及水平细胞中检测到免疫标记。GAD(67)免疫反应性在水平细胞中短暂表达，并在出生后第3周消失。然而，GAD(65)直到出生后第5天才开始发育。在无长突细胞和/或神经节细胞体中检测到免疫标记之前，在构成内网状层（IPL）的突起中检测到免疫标记。GAD转录本的出现与蛋白质的出现一致。还观察到GAD(67)基因的mRNA转录本的一种短暂形式，其包含一个额外外显子（ES-外显子），从出生到出生后第4周逐渐消失。这种形式合成一种截短的、无酶活性的蛋白质，其可能参与视网膜发育过程中高浓度存在的谷氨酸合成GABA的调节。
