Abstract

Spindle pole body (SPB) is the microtubule organizing center (MTOC) in yeast. It plays essential roles during many cellular processes, ranging from mitosis to karyogamy. Here, we used electron cryo-tomography (cryo-ET) and image processing to study SPB and its component purified from the budding yeast. The 3D images and models of SPB at various cell cycle stages were reconstructed by cryo-ET and were analyzed. The results reveal SPB as a cylindrical shaped structure composed of multiple layers. The central layers are arranged with a degree of crystalline order. By using subtomogram averaging methods, we studied the purified \"sheet\" from over-expressed Spc42p. Our analysis of the SPBs and its components provides new insights into the assembly of this organelle and its cellular function as an MTOC.