关键词: 高原鼢鼠, Prestin基因, 组织特异性表达, 地下空间定位

Abstract: The Plateau zokor (Eospalax baileyi) is a typical subterranean mole rat in Qinghai-Tibet plateau. Subterranean mole rat is a kind of animal which has the ability to orient space accurately. Prestin expressed specifically in cochlea is the protein related to the echolocation. In order to shed light on the relationship between prestin and underground spatial orientation of plateau zokor, the CDS sequence of plateau zokor prestin gene was cloned and compared with other species. The software PAML was used to analyze the adaptive evolution of amino acid sites in the prestin of plateau zokor., The expression levels of prestin mRNA in cochlea, tail, paw and nose were determined with real-time PCR according to the cloned sequence. The results indicated that the CDS sequence of the plateau zokor prestin was similar to those of six kinds of mammals such as human, rat, mouse, naked mole rat, rabbit and cow; and the amino acid sequences showed a relatively high degree of conservation with nine particular amino acid substitutions. No significantly positive selection site was detected with Test 2 model. The expression level of prestin mRNA in plateau zokor cochlea was significantly higher than that in plateau pika (P<0.05), and the prestin mRNA in plateau zokor cochlea was significantly higher than that in the paw and nose (P<0.01).The result above suggested that prestin not only is expressed in the cochlea, but also in paw, nose and tail of plateau zokor. Plateau zokors may perceive low frequency sound waves to accurately orient the space with assistance from their paws, noses and tails during their underground trunk life.

Key words: Plateau zokor (Eospalax baileyi), Prestin gene, Tissue specific expression, subterranean spatial orientation