摘要
用地高辛标记的寡核苷酸探针对GnRH受体在文昌鱼 (Branchiostomabelcheri)神经系统、哈氏窝和性腺中的定位和表达进行原位杂交研究。结果显示 ,神经系统中神经细胞、尤其是在中脑右侧延伸出与哈氏窝相接触的漏斗样结构中的神经细胞、哈氏窝上皮细胞以及雌雄性腺中生殖细胞都有GnRH受体mRNA杂交信号 ,信号物质分布于胞质 ,胞核为阴性。表明文昌鱼神经系统、哈氏窝和性腺都能合成GnRH受体 ,从而成为GnRH在脑、哈氏窝和性腺中的靶细胞。为GnRH刺激哈氏窝上皮细胞的分泌活动、调节性腺发育成熟和生殖活动 ,在分子水平上提供了确凿的证据。还讨论了文昌鱼漏斗样结构在调节哈氏窝分泌活动中的作用 ,一方面可介导脑与哈氏窝之间的信息传递和调节 ,另一方面作为刺激或抑制哈氏窝分泌活动的调节中枢。
Localization and expression of GnRH receptor (GnRHR) mRNA in the nervous system,Hatschek's pit and gonads of amphioxus, Branchiostoma belcheri ,were investigated immunohistochemically using digoxigenin labled oligonycleotide probe. The results showed that the nerve cells in midbrain and nerve tuber,the epithelia cells of Hatschek's pit and germocyte in testis and ovary of different development stages had GnRHR mRNA hybridization signal. It was worthwhile noting that some strong GnRHR mRNA hybridization signal were found for the first time in the funnel like structure,a part of midbrain extension. The signal substance distributed in the cytoplasm,but the nucleus showed negative reaction. These results in dicated that the nervous system,Hatschek's pit and gonads of amphioxus were all capable of synthesizing GnRH receptors,which acted as target cells of GnRH in the nervous system,Hatschek's pit and gonads. Thus,the present study provided an authentic proof that GnRH might stimulate the secretory activity of Hatschek's pit epithelia cells and regulate gonadal development and maturation and reproduction activity on molecular level. It was suggested that the infundibulum like structure might have two physiological functions:① to act as a “transformation station” mediating the informative transfer and regulation between brain and Hatschek's pit;②to be a regulation center to stimulate or inhibit the secretory act ivity of Hatschek's pit.<ekeyword><
基金
国家自然科学基金资助项目!(39870 12 0 )
关键词
文昌鱼
GNRH受体
神经系统
哈氏窝
原位杂交
Amphioxus
GnRH receptor
Nervous system
Hatschek’s pit
In situ hybridization
