A novel microtubule nucleation pathway for meiotic spindle assembly in oocytes

The meiotic spindle in oocytes is assembled in the absence of centrosomes, the major microtubule nucleation sites in mitotic and male meiotic cells.

A crucial, yet unresolved question in meiosis is how spindle microtubules are generated without centrosomes and only around chromosomes in the exceptionally large volume of oocytes.

the Subito complex from ovaries can nucleate microtubules from pure tubulin dimers. Collectively, microtubule nucleation regulated by Subito drives spatially restricted spindle assembly in oocytes.

Spatial and temporal regulation of microtubule nucleation is vital for the formation and maintenance of a functional spindle.

Collectively, tight regulation of Subito appears critical to assemble spindle microtubules around the chromosomes and to prevent their assembly anywhere else.

 It would be of great future interest to elucidate the regulatory mechanism of Subito in oocytes.