Fusion of the nuclei of two haploid eukaryotic cells
Karyogamy in the context of cell fusion. 1-haploid cells, 2-cell fusion, 3-single cell with two pronuclei, 4-fusing pronuclei (karyogamy), 5-diploid cell
Karyogamy is the final step in the process of fusing together two haploid eukaryotic cells, and refers specifically to the fusion of the two nuclei. Before karyogamy, each haploid cell has one complete copy of the organism's genome. In order for karyogamy to occur, the cell membrane and cytoplasm of each cell must fuse with the other in a process known as plasmogamy. Once within the joined cell membrane, the nuclei are referred to as pronuclei. Once the cell membranes, cytoplasm, and pronuclei fuse, the resulting single cell is diploid, containing two copies of the genome. This diploid cell, called a zygote or zygospore can then enter meiosis (a process of chromosome duplication, recombination, and division, to produce four new haploid cells), or continue to divide by mitosis. Mammalian fertilization uses a comparable process to combine haploid sperm and egg cells (gametes) to create a diploid fertilized egg.
The term karyogamy comes from the Greek karyo- (from κάρυον karyon) 'nut' and γάμος gamos 'marriage'.[1]
Karyogamy is the final step in the process of fusing together two haploid eukaryotic cells, and refers specifically to the fusion of the two nuclei. Before...
haploid nuclei close together in the same cell. This state is followed by karyogamy, where the two nuclei fuse and then undergo meiosis to produce spores...
migrate into each other's mycelia and pair up with the resident nuclei. Karyogamy is delayed, so that the compatible nuclei remain in pairs, called a dikaryon...
major lineages: mushrooms, rusts and smuts. Fusion of haploid nuclei (karyogamy) occurs in the basidia, club-shaped end cells. Shortly after formation...
new individual organism. The sexual fusion of haploid cells is called karyogamy, the result of which is the formation of a diploid cell called the zygote...
occurs, the two nuclei of two cells pair off and cohabit without fusing (karyogamy). This can be maintained for all the cells of the hyphae by synchronously...
nuclei fuse (karyogamy) and undergo homologous recombination facilitated by meiosis gene homologs. The recombination associated with karyogamy may primarily...
develops. The zygosporangium typically contains a single zygospore. Nuclear karyogamy and meiosis (sexual recombination) occur within it. Most species of Mucor...
eukaryotes, sporogenesis often occurs as a result of fertilization or karyogamy forming a diploid spore equivalent to a zygote. Therefore, zygospores...
period dikaryophase, by a pairwise fusion (karyogamy) of sexually different nuclei. In this case, karyogamy takes place simultaneously between the nuclei...
of fungi. These haploid, non-motile spores are the site of meiosis and karyogamy in oomycetes. A dormant oospore, when observed under an electron microscope...
fusion of two haploid gamete cells. Among sporogenic dikaryotic cells, karyogamy (the fusion of the two haploid nuclei) occurs to produce a diploid cell...
asci) is then formed, in which karyogamy (nuclear fusion) occurs. Asci are embedded in an ascocarp, or fruiting body. Karyogamy in the asci is followed immediately...
two unfused nuclei, i.e. one from each parent that eventually undergoes karyogamy and meiosis to complete the sexual cycle.[citation needed] Also the term...
plasmogamy is not immediately followed by the merging of the nuclei (called karyogamy). Instead, the nuclei from the two hyphae form pairs, initiating the dikaryophase...
conjugation, the macronucleus disintegrates, and a new one is formed by karyogamy of the micronuclei. Macronuclei contain hundreds to thousands of chromosomes...
is called plasmogamy. Actual fusion to form diploid nuclei is called karyogamy, and may not occur until sporangia are formed. Karogamy produces a diploid...
dikaryotic or heterokaryotic hyphae. The second step of fertilisation is karyogamy, the fusion of the nuclei to form a diploid zygote. In chytrid fungi,...
predominantly haploid, however, upon mating, the nuclei do not immediately fuse: karyogamy is delayed until the very onset of meiosis. The resulting mycelium is...
reproduction of ascomycete fungi, a variant of meiosis following an "extra" karyogamy (nuclear fusion) step. The hypothesized process would have transformed...
carpel. It encompasses both plasmogamy, the fusion of the protoplasts, and karyogamy, the fusion of the nuclei. When pollen lands on the stigma of the flower...
dikaryote cells. As the teliospore cells germinate, the nuclei undergo karyogamy and thereafter meiosis, giving rise to a four-celled basidium with haploid...
stress. The haploid nuclei of C. neoformans can undergo nuclear fusion (karyogamy) to become diploid. These diploid nuclei may then undergo meiosis, including...
characteristic dark color and spiky shape. The nuclei join in a process called karyogamy to form a zygote, which grows into a mature diploid zygomycete. A diploid...
and 1850s. A zygotic meiosis is a meiosis of a zygote immediately after karyogamy, which is the fusion of two cell nuclei. This way, the organism ends its...
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