7個地理種群小鼠TLR9基因的遺傳多樣性分析

冷冰霜 于立強 黃玲

摘要 [目的]分析我國7個地理種群小鼠TLR9基因的遺傳多樣性。[方法]利用PCR技術(shù)擴增并測序7個地理種群100個小鼠樣品的TLR9基因。使用MEGA 7.0、DnaSP等軟件對基因序列進行分析，計算遺傳距離、遺傳多樣性，并構(gòu)建系統(tǒng)發(fā)育樹。[結(jié)果]獲得的TLR9基因片段長度為1 030 bp，位于參與對病原體相關(guān)分子模式識別的LRR結(jié)構(gòu)域的編碼區(qū)，A、T、C、G的平均含量分別為22.9%、22.2%、32.8%和22.0%，各地理種群間堿基含量沒有明顯差異。通過計算各地理種群間遺傳距離及核苷酸多樣性發(fā)現(xiàn)，這7個地理種群小鼠TLR9基因序列較為保守，并無明顯遺傳分化。以褐家鼠（NM_198131） 作為外群構(gòu)建系統(tǒng)發(fā)育樹，其結(jié)果與遺傳多樣性分析相一致。[結(jié)論]7個地理種群小鼠TLR9基因遺傳多樣性較低，具有極高的保守性。

關(guān)鍵詞 小鼠;TLR9 基因;遺傳多樣性

中圖分類號 Q953文獻標識碼 A

文章編號 0517-6611（2019）10-0089-03

Abstract [Objective]To analyze the genetic diversity of TLR9 gene in Mus musculus from 7 geographical populations of China.[Method] PCR technology was used to amplify and sequence TLR9 gene of 100 mice samples in 7 geographical populations.Using MEGA 7.0，DnaSP and other software，the sequences of TLR9 gene were analyzed，the genetic distance and genetic diversity were calculated，and the phylogenetic tree was constructed.[Result]The length of TLR9 gene fragment was 1 030 bp.TLR9? gene was located in the encoding region of LRR domain， which was involved in the identification of pathogenrelated molecular patterns.The average content of bases A，T，C，G were 22.9%，22.2%，32.8% and 22.0% respectively.There was no significant difference in base composition among different geographical populations.Through calculating the genetic distance and nucleotide diversity among the geographical populations，it was found that TLR9 gene in M.musculus in 7 geographical populations was conservative，and there was no obvious genetic differentiation.The phylogenetic tree was constructed with Rattus norvegicus （NM_198131） as the outgroup，the results were consistent with the genetic diversity analysis.[Conclusion]The genetic diversity of TLR9 gene in M.musculus of 7 geographical populations was low，with high conservation.

Key words Mus musculus;TLR9 gene;Genetic diversity

小鼠（Mus musculus）是全球性分布的小型嚙齒類動物，其適應(yīng)性強、行動敏捷，活動范圍廣泛，主要棲息在與人類生產(chǎn)和生活密切相關(guān)的生境區(qū)域（室內(nèi)生境、室周生境及農(nóng)業(yè)耕作區(qū)等），是最常見的家棲鼠種之一[1]。小鼠與人類伴生，關(guān)系密切，作為易感宿主，其體內(nèi)外存在多種寄生蟲，可以攜帶多種病原體，并傳播多種人獸共患病，目前已發(fā)現(xiàn)的有20多種，如萊姆病、腎綜合征出血熱、恙蟲病、鼠疫和地方性斑疹傷寒等[2]。小鼠早在6 000萬年前便和人類共有同一祖先，與人類在基因組水平上的同源性高達93%。同時，其生理生化指標及其調(diào)控機制也與人類相同或相似，進一步為其作為人類疾病研究模型提供了強有力的證據(jù)[3-4]。……