Mitotic endosomes regulate spindle organization and function via Occludin and FIP5 binding

The genetic basis of vertebrate emergence is a major unanswered question in metazoan evolution. Understanding vertebrate-specific genes, such as Occludin (Ocln), may help answer this question. Here, we show that mammary glands lacking Ocln exhibit retarded branching, resulting from reduced cell proliferation. Interestingly, Ocln regulates spindle orientation and function, and its loss leads to a range of phenotypes, including prolonged prophase and failed nuclear and/or cytoplasmic division. Overall design: Luminal cells were extracted from control and Ocln-/- mice at 7-week stage. Then, RNA was isolated using RNA extraction kit.