铁因素对趋磁螺菌AMB-1磁小体形成及其相关基因表达的影响

Effects of Iron on Magnetosome Formation and Expression of mms13 ,mms6 and magA in Magenetospirillum magneticum AMB-1

目的 观察铁（Fe3＋）对趋磁螺菌AMB-1磁小体形成及相关基因表达的影响,为优化磁小体最适生长条件和探讨磁小体形成机制提供实验依据.方法 驯化的无磁性AMB-1接种到有Fe3＋或无Fe3＋培养基中培养,测定Cmag值和透射电镜研究磁小体形成,qRT-PCR检测磁小体相关基因mms13,mms6和magA表达.结果 在好氧条件下,有Fe3＋培养的AMB-1 Cmag值增长明显,磁小体呈短链状排列;无Fe3＋培养AMB-1无磁小体;有Fe3＋比无Fe3＋培养细胞mms13上调表达,magA下调表达.微氧条件下,有Fe3＋比无Fe3＋培养的AMB-1 Cmag值明显增高,磁小体颗粒较大,magA上调表达.结论 铁因素促进趋磁螺菌AMB-1磁小体形成,并明显影响mms13和magA基因表达.

Objective To investigate the effects of iron on magnetosome formation and the expression of mms13,mms6 and magA in Magnetospirillum magneticum AMB-1. This study is important for optimizing the optimal condition of magnetosome formation and will provide evidence for demonstrating the mechanism of magnetosome formation. Methods We incubated cultures of non-magnetic AMB-1 eells into EMSGM or EMSGM without ferric quinate. To investigate the effects of iron（ Fe2＋）on magnetosome formation by measuring Cmag value and transmission electron microscope. The expression of mms 13 ,mms6 and magA related to magnetosome formation was detected with qRT-PCR. Results In aerobic condition,the Cmag value of AMB-1 cultured in EMSGM increased obviously and magnetosomes align in short chains was found. There was no magnetosome in AMB-1 c.uhured in EMSGM without ferric quinate. The expression of mms13 was up-regulated, while magA was down-regulated. In mieroaerobic conditon,the Cmag value of AMB-1 cultured in EMSGM was higher and the particles of magnetu-somes were bigger than cells cultured in EMSGM without ferric quinate and the expression of magA was up-regulated. Conclusion Iron can promote magnetosome formation and affect the expression of mm313 and rams6 in Magnetospirillum. magneticum AMB -1.