nov基因的表达与脑的种系发育分化平行相关

THE EXPRESSION OF NOV GENE COINCIDES WITH DEVELOPMENT AND DIFFERENTIATION OF BRAIN DURING THE EVOLUTION FROM FISH TO MAMMALS

用地高辛标记的cRNA探针原位杂交组织化学方法研究了鲢、鸡、牛、犬和猫脑肾母细胞瘤过度表达基因阳性神经元的比较发育。结果显示 ,低等脊椎动物鲢脑仅有少量novmRNA阳性神经元 ,分布于延髓的迷走神经背核、三叉神经背核、丘脑前核、丘脑后核、下丘脑背侧核、下丘脑外侧核。鸡脑阳性神经元除广泛分布于脑干外 ,小脑、丘脑的多数核团、下丘脑的背侧核、腹侧核和后核以及大脑纹状体等多数脑区也有一定分布。哺乳动物牛、犬和猫脑中novmRNA阳性神经元广泛分布 ,在脑干、小脑、间脑和大脑都检测到强烈阳性信号。以上结果表明 ,在从低等脊椎动物到高等脊椎动物的进化过程中nov基因的表达也从低级中枢向高级中枢扩展 ,提示该基因的表达与脑的种系发育、脑功能的分化平行相关。

The nov gene is a founding member of the expanding CCN family of genes, which encode proteins reported to be involved in a variety fundamental biological functions. Our previous studies have confirmed that nov gene might be involved in the acquisition of specific functions during postnatal development of rat central nervous system. The aim of this study is to reveal the relationship between nov expression and development, differentiation of brain during the evolution from lower vertebrate——fish to higher vertebrate——mammals. Comparative distribution of nov mRNA positive neurons in the brain of Silver carp, chicken, cattle, dog and cat was studied by using in situ hybridization histochemistry. The results were as follows: a few of nov mRNA positive neurons were detected in dorsal motor nucleus of vagus, motor nucleus of the trigeminal nerve, anterior thalamic nucleus, posterior thalamic nucleus, dorsal hypothalamic nucleus and lateral hypothalamic nucleus of lower vertebrate Silver carp. In addition to the pons positive neurons were also found in cerebellum, most nucleus of thalamus and hypothalamus, and corpus striatum of chicken. Whereas a lot of nov mRNA positive neurons were widely localized in the brain of mammals—cattle, dog and cat, strong positive signal was found in pons, cerebellum, thalamus, hypothalamus and cerebrum of these species. Our results indicated that nov gene is very conservative during the evolution of brain from lower vertebrate—fish to higher vertebrate—mammals, and the expression of nov gene coincided with the development and structure and function differentiation of brain.