@article{oai:oist.repo.nii.ac.jp:00000995,
 author = {Matsu-ura, Toru and Shirakawa, Hideki and Suzuki, Kenichi G. N. and Miyamoto, Akitoshi and Sugiura, Kotomi and Michikawa, Takayuki and Kusumi, Akihiro and Mikoshiba, Katsuhiko},
 issue = {1},
 journal = {Scientific Reports},
 month = {Mar},
 note = {In most species, fertilization induces Ca(2+) transients in the egg. In mammals, the Ca(2+) rises are triggered by phospholipase Czeta (PLCzeta) released from the sperm; IP3 generated by PLCzeta induces Ca(2+) release from the intracellular Ca(2+) store through IP3 receptor, termed IP3-induced Ca(2+) release. Here, we developed new fluorescent IP3 sensors (IRIS-2s) with the wider dynamic range and higher sensitivity (Kd = 0.047-1.7 muM) than that we developed previously. IRIS-2s employed green fluorescent protein and Halo-protein conjugated with the tetramethylrhodamine ligand as fluorescence resonance energy transfer (FRET) donor and acceptor, respectively. For simultaneous imaging of Ca(2+) and IP3, using IRIS-2s as the IP3 sensor, we developed a new single fluorophore Ca(2+) sensor protein, DYC3.60. With IRIS-2s and DYC3.60, we found that, right after fertilization, IP3 concentration ([IP3]) starts to increase before the onset of the first Ca(2+) wave. [IP3] stayed at the elevated level with small peaks followed after Ca(2+) spikes through Ca(2+) oscillations. We detected delays in the peak of [IP3] compared to the peak of each Ca(2+) spike, suggesting that Ca(2+)-induced regenerative IP3 production through PLC produces small [IP3] rises to maintain [IP3] over the basal level, which results in long lasting Ca(2+) oscillations in fertilized eggs.},
 title = {Dual-FRET imaging of IP3 and Ca2+ revealed Ca2+-induced IP3 production maintains long lasting Ca2+ oscillations in fertilized mouse eggs},
 volume = {9},
 year = {2019}
}