高原鼢鼠(Myospalaxbaileyi)终生营地下洞道生活,具有较强的学习记忆能力和定位洞道中障碍物的能力。又头框蛋白P2(forkheadboxp2,FOXP2)是一种与口面部协调、运动协调功能有关,并且与学习记忆、以及定位功能有密切联系的转录因子。为了研究和探讨foxP2基因与高原鼢鼠发达的学习记忆能力之间的关系,我们克隆了高原鼢鼠foxP2基因的编码区序列;以地面动物高原鼠兔为对照,应用real.timePCR和ElWestemblot分别测定高原鼢鼠脑组织中foxP2mRNA和FOXP2蛋白的表达水平;应用免疫组织化学法检测FoxP2蛋白在高原鼢鼠脑组织不同区域中的表达。结果显示:(1)与其它哺乳类动物相比,高原鼢鼠foxP2编码区序列相对保守,但其编码的氨基酸序列显示存在两个特殊的氨基酸残基突变;(2)高原鼢鼠(foxP2mRNA的表达量极显著高于高原鼠兔俨〈O.01);(3)高原鼢鼠FOXP2蛋白的表达量极显著高于高原鼠兔俨〈O.01);(4)FOXP2蛋白在高原鼢鼠脑组织不同区域均有表达,其中以大脑皮层、丘脑和纹状体区域表达量较高。本研究结果提示,高原鼢鼠发达的学习记忆能力与foxp2基因在脑组织中的高表达有着密切的联系。
Plateau zokor (Myospalax baileyi) is a subterranean mammal. Plateau zokor has high learning and memory ability, and can determine the location of blocking obstacles in their tunnels. Forkhead box p2 (FOXP2) is a transcription factor implicated in the neu- ral control of orofacial coordination and sensory-motor integration, particularly with respect to learning, memory and vocalization. To explore the association offoxP2 with the high learning and memory ability of plateau zokor, the cDNA offoxP2 of plateau zokor was sequenced; by using plateau pika as control, the expression levels offoxP2 mRNA and FOXP2 protein in brain of plateau zokor were determined by real-time PCR and Western blot, respectively; and the location of FOXP2 protein in the brain of plateau zokor was determined by immunohistochemistry. The result showed that the cDNA sequence of plateau zokorfoxP2 was similar to that of other mammals and the amino acid sequences showed a relatively high degree of conservation, with the exception of two particular amino acid substitutions [a Gln (Q)-to-His (H) change at position 231 and a Ser (S)-to-Ile (I) change at position 235]. Higher expression levels offoxP2 mRNA (3-fold higher) and FOXP2 protein (〉2-fold higher) were detected in plateau zokor brain relative to plateau pika brain. In plateau zokor brain, FOXP2 protein was highly expressed in the cerebral cortex, thalamus and the striatum (a basal ganglia brain region). The results suggest that the high learning and memory ability of plateau zokor is related to the high expression levels offoxP2 in the brain.