Karyogamy is the process where haploid nuclei fuse to form a diploid nucleus during yeast mating. We devised a novel genetic screen that identified five new karyogamy (KAR) genes and three new cell fusion (FUS) genes. The kar mutants fell into two classes that represent distinct events in the yeast karyogamy pathway. Class I mutations blocked congression of the nuclei due to cytoplasmic microtu...

The cover shows the sun over a nuclear power station. Tritium is generated by nuclear fusion reactions in the sun and would be generated in terrestrial nuclear fusion power production. It is also produced as part of the fuel cycle in current nuclear fi ssion power production and has several uses in industry.

Regulation of nuclear envelope dynamics is an important example of the universal phenomena of membrane fusion. The signalling molecules involved in nuclear membrane fusion might also be conserved during the formation of both pronuclear and zygote nuclear envelopes in the fertilised egg. Here, we determine that class-I phosphoinositide 3-kinases (PI3Ks) are needed for in vitro nuclear envelope f...

Fusion reactions below the Coulomb barrier provide new insights into multidimensional quantum tunneling, nuclear reaction dynamics and nuclear structure.1), 2) These reactions are also of considerable interest to nuclear astrophysics. The evolution of main sequence stars, in particular stellar nucleosynthesis is governed by subbarrier fusion.3) It may be worthwhile to review some of the basic a...

Nuclear membrane fusion is the last step in the mating pathway of the yeast Saccharomyces cerevisiae. We adapted a bioinformatics approach to identify putative pheromone-induced membrane proteins potentially required for nuclear membrane fusion. One protein, Prm3p, was found to be required for nuclear membrane fusion; disruption of PRM3 caused a strong bilateral defect, in which nuclear congres...

We discuss the effects of fast nuclear excitations on heavy-ion fusion reactions at energies near and below the Coulomb barrier. Using the fusion of two 40 Ca nuclei as an example and the inversion method, we show that the mass renormalization induced by fast nuclear excitations leads to a large surface diffuseness in the effective potential for heavy-ion fusion reactions.