Spindle tubulin and MTOC asymmetries may explain meiotic drive in oocytes

In the first meiotic division (MI) of oocytes, the cortically positioned spindle causes bivalent segregation in which only the centre-facing homologue pairs are retained. ‘Selfish’ chromosomes are known to exist, which bias their spindle orientation and hence retention in the egg, a process known as ‘meiotic drive’.

 The reason for the establishment of MTOC asymmetry remains unknown

Future work on the ‘strong centromere’ hypothesis should therefore focus on how centromere size influences recruitment of Spindle Assembly Checkpoint proteins and Chromosomal Passenger Complex components to the centromere/kinetochore, both pathways having a potential impact on the ability of the homologue pair to interact with and then destabilise spindle microtubules46,47,48.

the relationship by which centromeric CENPs seed formation of kinetochores is currently under intense investigation41, and involves the influence of pericentromeric heterochromatin, as well as CENP containing domains.