Lenoir D, Battenberg E, Kiel M, Bloom F E, Milner R J
J Neurosci. 1986 Feb;6(2):522-30. doi: 10.1523/JNEUROSCI.06-02-00522.1986.
The rat brain-specific polypeptide 1B236 was previously characterized by molecular cloning and nucleotide sequence determination of its mRNA. It has been shown to exist in rat brain in discrete neuronal circuits, primarily as a 100,000 Da glycoprotein. We now have determined the time course of expression of 1B236 mRNA and protein in rat brain during fetal and postnatal development, detecting 1B236 mRNA by RNA blotting and assaying 1B236 protein by electroblotting and radioimmunoassay with antibodies against synthetic peptides. By both indices, expression of the 1B236 gene products is found to be a relatively late event in neuronal development. 1B236 mRNA is first detectable in extracts of whole rat brain at Postnatal Day 5 (PD 5) and increases to a maximum concentration at PD 25. In extracts of dissected brain regions, 1B236 mRNA is first detectable at PD 5 in hindbrain and cerebellum, at PD 9 in midbrain/diencephalon, but not until PD 13 in telencephalon. The appearance of 1B236 protein follows a very similar time course to that of its mRNA in both whole brain and dissected brain regions, suggesting that the expression of the protein during development is regulated largely by transcription of its mRNA. The pattern of 1B236 expression was confirmed by immunocytochemical localization of 1B236 protein: Immunoreactive material can be detected first in spinal cord at PD 3-PD 5 and then appears in progressively more rostral brain regions in increasingly older animals. Several brain regions, however, that do not contain 1B236 immunoreactivity in the adult, such as optic nerve and somatic efferent cranial nerve nuclei, show transient expression of 1B236 during postnatal development.(ABSTRACT TRUNCATED AT 250 WORDS)
大鼠脑特异性多肽1B236先前已通过其mRNA的分子克隆和核苷酸序列测定进行了表征。研究表明，它以100,000 Da糖蛋白的形式主要存在于大鼠脑的离散神经回路中。我们现在已经确定了1B236 mRNA和蛋白在大鼠脑胎儿期和出生后发育过程中的表达时间进程，通过RNA印迹检测1B236 mRNA，并使用针对合成肽的抗体通过电印迹和放射免疫测定法检测1B236蛋白。通过这两个指标发现，1B236基因产物的表达在神经元发育中是一个相对较晚的事件。1B236 mRNA在出生后第5天（PD 5）首次在全大鼠脑提取物中可检测到，并在PD 25时增加到最大浓度。在解剖的脑区提取物中，1B236 mRNA在PD 5时在后脑和小脑中首次可检测到，在PD 9时在中脑/间脑中可检测到，但直到PD 13时才在端脑中可检测到。1B236蛋白的出现与其mRNA在全脑和解剖脑区中的时间进程非常相似，这表明该蛋白在发育过程中的表达主要受其mRNA转录的调节。1B236蛋白的免疫细胞化学定位证实了其表达模式：在PD 3 - PD 5时首先在脊髓中可检测到免疫反应性物质，然后在年龄越来越大的动物中逐渐出现在更靠前的脑区。然而，一些在成年动物中不含有1B236免疫反应性的脑区，如视神经和躯体传出脑神经核，在出生后发育过程中显示出1B236的短暂表达。（摘要截短至250字）
