The genetic integrity of organisms relies on the proper partitioning of the genome between the two daughter cells during mitosis. Efficient formation of a bipolar spindle is essential for the proper chromosome segregation. During my PhD thesis, we took advantage of the highly stereotypical cell divisions in Caenorhabditis elegans embryos to study the formation and the maintenance of a bipolar spindle. In the first part of my thesis, we identified a key role for the microtubule depolymerase KLP-7 in promoting centrosome separation at the two cell stage. Our data indicate that this phenotype depends on cell polarity. In the second part of my thesis, we investigated the role of kinetochores during bipolar spindle maintenance. We showed that kinetochores become essential to maintain the bipolar spindle in the absence of cortical forces. Overall my research implies that the establishment and the maintenance of a bipolar spindle is regulated in a cell lineage specific mechanisms.