Nuclear gene is a gene located in the cell nucleus of an eukaryote. The term is used to distinguish nuclear genes from the genes in the mitochondrion, or in case of plants, also the chloroplast, which host their own genetic system and can produce proteins from scratch. The term "gene" most often refers to nuclear genes.

Nuclear genes include the "original" genes of the eukaryotes. Mitochondria and chloroplasts are thought to have originated from symbiotic bacteria that are now so integrated to their host cells that they function as integral cell components or organelles.^[1][2] Both of these organelles still retain a small genome. Most of the organelles proteins are products of nuclear genes. Many of these genes have been moved to the nucleus during evolution. These proteins are produced in the cytoplasm like all nuclear gene products and then transported to the organelle.

A example of the DNA sequence and structure of a plant nuclear gene can be found here.

References

1. ↑ Enrique Lopez-Juez and Kevin A. Pyke ''Plastids unleashed: their development and their integration in plant development'' Int. J. Dev. Biol. 49: 557 - 577 (2005) (Free full text)
2. ↑ Hoffmeister M, Martin W ''Interspecific evolution: microbial symbiosis, endosymbiosis and gene transfer.'' Environ Microbiol. 2003 Aug;5(8):641-9.