Zoeller R T, Lebacq-Verheyden A M, Battey J F
Laboratory of Neurochemistry, National Institute of Neurological, Communicative Disorders and Stroke, Bethesda, MD 20892.
Peptides. 1989 Mar-Apr;10(2):415-22. doi: 10.1016/0196-9781(89)90052-1.
There are two distinct mRNAs that encode the precursor to gastrin-releasing peptide (GRP) in rat brain. These two messages arise from separate transcription initiation sites located approximately 400 base pairs apart, which are presumably regulated by separate promoters. In the present study, we mapped the distribution of neurons containing GRP mRNAs by in situ hybridization using cRNA and synthetic DNA probes specific for the 1.5 kb GRP transcript and probes complementary to both the 1.5 kb and 1.1 kb transcripts. The distribution of neurons expressing GRP mRNA appears to be wider than that previously observed by immunohistochemical studies, suggesting an important functional role for this neuropeptide in a number of brain regions. We detected the 1.5 kb transcript only in cingulate cortex, Ammon's horn of the hippocampus and in subiculum. In contrast, the probe which hybridized to both GRP mRNAs labeled a broad range of brain areas, including those containing the 1.5 kb mRNA. These data suggest that the 1.5 kb mRNA encoding rat GRP is expressed only in specific parts of the limbic system, whereas the expression of the 1.1 kb GRP message is more widespread.
在大鼠脑中，有两种不同的信使核糖核酸（mRNA）编码胃泌素释放肽（GRP）前体。这两种信使核糖核酸来自相距约400个碱基对的不同转录起始位点，推测受不同启动子调控。在本研究中，我们使用针对1.5 kb GRP转录本的cRNA和合成DNA探针以及与1.5 kb和1.1 kb转录本均互补的探针，通过原位杂交绘制了含有GRP mRNA的神经元分布图谱。表达GRP mRNA的神经元分布似乎比先前免疫组织化学研究观察到的更广泛，表明这种神经肽在多个脑区具有重要的功能作用。我们仅在扣带回皮质、海马的海马角和下托中检测到1.5 kb转录本。相比之下，与两种GRP mRNA均杂交的探针标记了广泛的脑区，包括含有1.5 kb mRNA的区域。这些数据表明，编码大鼠GRP的1.5 kb mRNA仅在边缘系统的特定部位表达，而1.1 kb GRP信使核糖核酸的表达更为广泛。
