Tethered To Telomeres: Characterizing The Form And Dynamic Elasticity Of Tethers In Anaphase Crane-Fly Spermatocytes

Elastic tethers connect sister chromosomes during anaphase in a broad range of animal cells, likely aiding in communication and coordination of movement. Calyculin A prevents dephosphorylation of tethers by protein phosphatase 1 (PP1) and, consequently, causes them to remain elastic throughout anaphase, resulting in backward movement. In my thesis experiments, I further explore the composition and behaviour of tethers. I expand upon existing research with Calyculin A, elucidating an optimal working concentration of 10 nM for investigating the reversibility of this drug on backward movement when rinsed out at various stages. I show that PP1 is critical during the onset of anaphase and that backward movement is not readily reversible. I also support the existing notion that tethers are made of titin, disproving the hypothesis that tethers are made of DNA. These contributions further enhance our understanding of tether composition and regulation during a central mechanistic phase of cell division.