How are sister kinetochores mono-orientated during meiosis I?
One of the modifications that distinguishes meiosis I chromosome segregation from that in meiosis II and mitosis is kinetochore mono-orientation. Molecular mechanisms accomplishing this have been studied in other eukaryotic model organisms; however, it is assumed that they are not applicable to mammalian germ cells. One reason for this is that the centromeric DNA structure, on which the kinetochore is assembled, exhibits a large degree of diversity between species; another is that the molecules which have been found to play a role in mono-orientation, show very low conservation. Therefore the mechanism that determines kinetochore orientation in mammalian meiosis I remains totally unclear. We are taking a candidate approach, as well as interaction-based screening, to identify the relevant molecules. We are also testing whether the bi-orientated sister kinetochore configuration in mitotic cells can be converted to a mono-orientated arrangement.
