高原鼢鼠血红蛋白基因鉴定、表达及其分子进化分析  

Hemoglobin gene identification,expression and molecular evolution analysis in Eospalax baileyi

作　　者：鲁松松 赵夏下 祁重霞 杜雨薇 LU Songsong;ZHAO Xiaxia;QI Chongxia;DU Yuwei(College of Forestry,Gansu Agricultural University,Lanzhou 730070,China)

机构地区：[1]甘肃农业大学林学院,甘肃兰州730070

出　　处：《中山大学学报（自然科学版）（中英文）》2022年第4期49-59,共11页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：甘肃农业大学科技创新基金(2017RCZX-23,GAU-XKJS-2018-101);甘肃省青年科技基金计划(18JR3RA184)。

摘　　要：结合比较基因组、转录物组、分子进化和蛋白质物理化学性质及结构等分析方法,探讨高原鼢鼠Eospalax baileyi血红蛋白(Hb,hemoglobin)的α、β基因簇结构、基因表达模式及正选择位点对蛋白质结构的潜在影响等,旨在研究高原鼢鼠Hb氧亲和力升高的机理。结果表明:高原鼢鼠的α和β基因簇分别含有3个α(5ʹ-α^(E),αA,αQ-3ʹ)和7个β(5ʹ-ε,γ,γ1,γ,σ(pesudo),β1,β2(pesudo)-3ʹ)基因;成体高原鼢鼠除表达常规的成体Hb基因α^(A)和β1外,还表达了胚胎α^(E)基因;Hbβ1亚基血红素“口袋”开口处12个氨基酸残基的突变,使得该区域稳定性和亲水性增强,口袋(活性中心)体积也稍有增加。高原鼢鼠较高Hb氧亲和力的主要原因可能是其胚胎型α^(E)基因在成体中的表达,同时α^(E)和β1亚基稳定性增加,有利于高氧亲和力的α^(E)型Hb(α^(E)β1)2积累到较高的浓度。本文首次发现α^(E)基因在成体哺乳动物中被高表达,这可能是极端低氧环境诱导的,也可能是α^(E)基因调控区域遗传基础的改变引起的,具体机制尚待进一步验证。The study was aimed to reveal the mechanism of elevated hemoglobin oxygen affinity of Plateau zokor(Eospalax baileyi).By using a comparative genomic and transcriptomic analysis of the α and β gene clusters in the plateau zokor to characterize the changes in the size and membership composition of theαandβgene families within the Spalacidae,the study evaluated the evolutionary changes in the developmental regulation of gene expression of the plateau zokor and explored the potential impact of positive selection sites on protein structure and function.The results showed that the plateau zokorαand β gene clusters contain threeα(5ʹ-α^(E),α^(A),αQ-3ʹ)and seven β(5ʹ-ε,γ,γ1,γ2,σ(pesudo),β1,β2(pesudo)-3ʹ)genes respectively;in addition to the conventional adult expression genes αA and β1,adult plateau zokor expressed an extra embryonic α^(E) gene;the twelve amino acid mutations on heme“pocket”opening of β1 subunit might be able to increase the stability and hydrophilicity of the region,and slightly increases the volume of the pocket(active center).The results also suggested that the abnormally high oxygen affinity of plateau zokor might result from the expression of embryonic α^(E) gene in adults;the increased stability of α^(E) and β1 subunits and the decrease ofαA subunit stability may lead to accumulation of α^(E) type Hb(α^(E)β1)_(2) to a concentration similar to α A type(αAβ1)2.It was the first report that the α^(E) gene is highly expressed in adult mammals,this phenomenon may be induced by extreme low oxygen environment,or it may be caused by changes in the genetic basis of the α^(E) gene regulatory region.The specific mechanism needs further study.

关 键 词：高原鼢鼠Eospalax baileyi 血红蛋白 氧亲和力 基因表达 

分 类 号：Q71[生物学—分子生物学]