Challenges and triumphs in cryo-electron tomography

Cryo-electron tomography has stepped fully into the spotlight. Enthusiasm is high. Fortunately for us, this is an exciting time to be a cryotomographer, but there is still a way to go before declaring victory. Despite its potential, cryo-electron tomography possesses many inherent challenges. How do we image through thick cell samples, and possibly even tissue? How do we identify a protein of interest amidst the noisy, crowded environment of the cytoplasm? How do we target specific moments of a dynamic cellular process for tomographic imaging? In this review, we cover the history of cryo-electron tomography and how it came to be, roughly speaking, as well as the many approaches that have been developed to overcome its intrinsic limitations. [Display omitted] Timeline of major cryo-EM milestones discussed in the text. Citations for each event are as follows: (1) (1979): Heuser et al., 1979; (2) (2004): Xuong et al., 2004; (3) (2007): Marko et al., 2007; (4) (2008): NA; (5) (2012): Brilot et al., 2012 and Campbell et al., 2012; (6) (2014/VPP): Danev et al., 2014; (7) (2014/cryo-PALM): Chang et al., 2014; (8) (2018): Fuest et al., 2018; (9) (2019): Fuest et al., 2019; (10) (2017): Chen et al., 2017. Biochemistry; Cell biology; Structural biology