FIGURE 2.

Historical overview of GECI development. Selected GECIs are plotted with y-axis being the publication year and x-axis being the peak emission wavelength. The template FPs include ones based on BFP (Zhao et al., 2011), YFP (Baird et al., 1999), GFP (Nakai et al., 2001; Tian et al., 2009; Zhao et al., 2011; Akerboom et al., 2013; Dana et al., 2019; Zhang et al., 2021), mNeonGreen (Subach et al., 2020; Zarowny et al., 2020), mApple (Zhao et al., 2011; Dana et al., 2016), mRuby (Akerboom et al., 2013; Dana et al., 2016), FusionRed (Shen et al., 2018), and mIFP (Qian et al., 2019, 2020).