NUCLEAR-FUSION IN THE YEAST SACCHAROMYCES-CEREVISIAE

Karyogamy, or nuclear fusion, is the process during mating by which tw o haploid yeast nuclei fuse to produce a single diploid nucleus. Karyo gamy occurs in two major steps: microtubule-dependent nuclear congress ion followed by fusion of the nuclear envelope membranes, Many of the proteins required for karyogamy have been discovered to act in related processes during mitotic growth. Accordingly, yeast karyogamy has bec ome an important model system to investigate critical functions of the cytoplasmic microtubules and the microtubule organizing center, the n uclear envelope, and the endoplasmic reticulum.