A High-Resolution Genome-Wide CRISPR/Cas9 Viability Screen Reveals Structural Features and Contextual Diversity of the Human Cell-Essential Proteome.

To interrogate genes essential for cell growth, proliferation and survival in human cells, we carried out a genome-wide clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 screen in a B-cell lymphoma line using a custom extended-knockout (EKO) library of 278,754 single-guide RNAs (sgRNAs) that targeted 19,084 RefSeq genes, 20,852 alternatively spliced exons, and 3,872 hypothetical genes. A new statistical analysis tool called robust analytics and normalization for knockout screens (RANKS) identified 2,280 essential genes, 234 of which were unique. Individual essential genes were validated experimentally and linked to ribosome biogenesis and stress responses.

Quantitative analysis of cytokinesis in situ during C. elegans postembryonic development.

The physical separation of a cell into two daughter cells during cytokinesis requires cell-intrinsic shape changes driven by a contractile ring. However, in vivo, cells interact with their environment, which includes other cells. How cytokinesis occurs in tissues is not well understood.

In situ imaging in C. elegans reveals developmental regulation of microtubule dynamics.

Microtubules (MTs) are cytoskeletal polymers that undergo dynamic instability, the stochastic transition between growth and shrinkage phases. MT dynamics are required for diverse cellular processes and, while intrinsic to tubulin, are highly regulated. However, little is known about how MT dynamics facilitate or are regulated by tissue biogenesis and differentiation.

Dividing in epithelia: cells let loose during cytokinesis.

Epithelia must maintain barrier function-protecting interior tissues from a variable external environment-even while their cells divide. In the previous issue of Developmental Cell, Guillot and Lecuit (2013), Founounou et al. (2013), and Herszterg et al.