Expression patterns of key iron and oxygen metabolism genes during magnetosome formation in Magnetospirillum gryphiswaldense MSR-1

Authors

  • Qing Wang,

    1. State Key Laboratories for Agro-biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
    2. France–China Bio-mineralization and Nano-structure Laboratory, Beijing, China
    Search for more papers by this author
  • Jin-Xin Liu,

    1. State Key Laboratories for Agro-biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
    2. France–China Bio-mineralization and Nano-structure Laboratory, Beijing, China
    Search for more papers by this author
  • Wei-Jia Zhang,

    1. State Key Laboratories for Agro-biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
    2. Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
    Search for more papers by this author
  • Tong-Wei Zhang,

    1. State Key Laboratories for Agro-biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
    2. France–China Bio-mineralization and Nano-structure Laboratory, Beijing, China
    3. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China
    Search for more papers by this author
  • Jing Yang,

    1. State Key Laboratories for Agro-biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
    2. France–China Bio-mineralization and Nano-structure Laboratory, Beijing, China
    Search for more papers by this author
  • Ying Li

    Corresponding author
    1. France–China Bio-mineralization and Nano-structure Laboratory, Beijing, China
    • State Key Laboratories for Agro-biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
    Search for more papers by this author

Correspondence: Ying Li, State Key Laboratory of Agro-biotechnology and College of Biological Sciences, China Agricultural University, Beijing, 100193, China.

Tel.: +86 10 6273 3751;

fax: +86 10 6273 2012;

e-mail: yingli528@vip.sina.com

Abstract

To evaluate the expression patterns of genes involved in iron and oxygen metabolism during magnetosome formation, the profiles of 13 key genes in Magnetospirillum gryphiswaldense MSR-1 cells cultured under high-iron vs. low-iron conditions were examined. Cell growth rates did not differ between the two conditions. Only the high-iron cells produced magnetosomes. Transmission electron microscopy observations revealed that magnetosome formation began at 6 h and crystal maturation occurred from 10 to 18 h. Real-time polymerase chain reaction analysis showed that expression of these genes increased during cell growth and magnetosome synthesis, particularly for ferric reductase gene (fer6) and ferrous transport system-related genes feoAB1, feoAB2, sodB, and katG. The low-iron cells showed increased expression of feoAB1 and feoB2 from 12 to 18 h but no clear expression changes for the other genes. Expression patterns of the genes were divided by hierarchical clustering into four clusters for the high-iron cells and three clusters for the low-iron cells. Each cluster included both iron and oxygen metabolism genes showing similar expression patterns. The findings indicate the coordination and co-dependence of iron and oxygen metabolism gene activity to achieve a balance during the biomineralization process. Future transcriptome analysis will help elucidate the mechanism of biomineralization in MSR-1 magnetosome formation.

Ancillary