About the Authors

Chiemi Noguchi

Contributed equally to this work with: Chiemi Noguchi, Yoshio Araki

Affiliation Graduate School of Biosphere Science, Hiroshima University, Higashi-hiroshima, Hiroshima, Japan

Yoshio Araki

Contributed equally to this work with: Chiemi Noguchi, Yoshio Araki

Affiliation Graduate School of Biosphere Science, Hiroshima University, Higashi-hiroshima, Hiroshima, Japan

Daisuke Miki

Affiliation Tosoh Co., Ayase, Kanagawa, Japan

Noriaki Shimizu

shimizu@hiroshima-u.ac.jp

Affiliation Graduate School of Biosphere Science, Hiroshima University, Higashi-hiroshima, Hiroshima, Japan

Competing Interests

One of the authors (DM) is employed by a commercial company (Tosoh, Co.). The combined method described in this paper (IR/MAR-Dhfr fusion method) is already applied for a patent (JP2011-101610), where all the authors in this paper are the inventors and both Hiroshima University and Tosoh, Co. are the co-applicants. On the other hand, the IR/MAR plasmid that is described in the submitted article is already covered by an international patent (PCT/JP2005/020972). The plasmid is currently sold from Transgenic Inc. Japan, under the license from the patent owner, Hiroshima University. Any researcher may obtain it after purchasing the plasmid or after contracting with Hiroshima University for its usage. Therefore, this does not alter the authors’ adherence to all the PLOS ONE policies on sharing data and materials. Besides that, the authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: NS. Performed the experiments: CN YA DM. Analyzed the data: CN YA DM NS. Contributed reagents/materials/analysis tools: CN, YA DM. Wrote the paper: NS.