MOS7

MOS7 is a nuclear-pore-associated protein of Arabidopsis thaliana required for normal reproductive cell division. Although the nuclear pore complex is familiar as a transport gateway, some of its components also have roles during mitosis, when nuclear organization is extensively rebuilt.

Guen Tae Park and colleagues examined a loss-of-function MOS7 mutant. Developing pollen showed disorganized microtubules, defective spindle apparatus formation and abnormal division; female reproductive development and embryonic development were also affected. A transgene carrying functional MOS7 rescued the reproductive defects, making the attribution to the disrupted gene stronger than a comparison of unrelated abnormal and normal plants.^[ref] The experiments establish a requirement for MOS7, while leaving details of its molecular action on the division machinery open.