Characterizing the Effects of Jasplakinolide on Mesostoma Ehrenbergii Primary Spermatocytes to Study the Role of Actin during Chromosome Movement

My thesis investigated actins involvement in chromosome movement and function in the spindle. Generally, its thought that microtubules drive chromosome movement. However, when microtubules are depolymerized using nocodazole in Mesostoma ehrenbergii, chromosomes continue to move. To determine what proteins may contribute to chromosome movement, I targeted actin using an actin-stabilizing drug, jasplakinolide. I targeted actin because it has been found in the meiotic spindle of other cell types. Additionally, myosin has been implicated in Mesostoma chromosome movement, suggesting actin may be present since they work together in other systems. Jasplakinolide altered chromosome oscillation speeds and caused the precocious furrow to move and ingress towards a single pole at random, causing one side of the cell to become larger. The spindle pole of the larger half-cell moved along the cell periphery towards the opposite pole. My results suggest actin is involved in chromosome movement along with other non-microtubule spindle elements.