What is "supergene"

a. (context geology of a mineral English) leached and then deposited by descending waters n. (context genetics English) A group of neighbouring genes on a chromosome that are inherited together because of close genetic linkage and are functionally related in an evolutionary sense.

A supergene is a group of neighbouring genes on a chromosome which are inherited together because of close genetic linkage and are functionally related in an evolutionary sense, although they are rarely co-regulated genetically.

Supergenes have cis-effects due to multiple loci (which may be within a gene, or within a single gene's regulatory region), and tight linkage. They are classically polymorphic, and different elements code for different fitness effects which combine to form a coherent or epistatic whole. The two classic supergenes are (1) the Primula heterostyly locus, which controls " pin" and " thrum" types, and (2) the locus controlling Batesian mimetic polymorphism in Papilio memnon butterflies. For example, pin and thrum morphs of Primula have effects on genetic compatibility (pin style x thrum pollen, or thrum style x pin pollen matings are successful, while pin x pin, and thrum x thrum matings are rarely successful due to pollen-style incompatibility), and have different style length, anther height in the corolla tube, pollen size, and papilla size on the stigma. Each of these effects is controlled by a different locus in the same supergene, but recombinants are occasionally found with traits combining those of "pin" and "thrum" morphs.

Gene complexes, in contrast, are simply tightly linked groups of genes, often created via gene duplication (sometimes called segmental duplication if the duplicates remain side-by-side). Here, each gene has similar though slightly diverged function. For example, the human major histocompatibility complex (MHC) region is a complex of tightly linked genes all acting in the immune system, but has no claim to be a supergene, even though the component genes very likely have epistatic effects and are in strong disequilibrium due in part to selection.

No supergene has yet been characterized to the functional DNA level, but work is proceeding in a number of species.

The earliest use of the term "supergene" may be in an article by A. Ernst (1936) in the journal Archiv der Julzus Klaus-stiftung fur Vererbungsforschung, Sozialanthropologie und Rassenhygiene.

In ore deposit geology, supergene processes or enrichment are those that occur relatively near the surface as opposed to deep hypogene processes. Supergene processes include the predominance of meteoric water circulation with concomitant oxidation and chemical weathering. The descending meteoric waters oxidize the primary ( hypogene) sulfide ore minerals and redistribute the metallic ore elements. Supergene enrichment occurs at the base of the oxidized portion of an ore deposit. Metals that have been leached from the oxidized ore are carried downward by percolating groundwater, and react with hypogene sulfides at the supergene-hypogene boundary. The reaction produces secondary sulfides with metal contents higher than those of the primary ore. This is particularly noted in copper ore deposits where the copper sulfide minerals chalcocite CuS, covellite CuS, digenite CuS, and djurleite CuS are deposited by the descending surface waters.

All such processes take place at essentially atmospheric conditions, 25 °C and atmospheric pressure.

Supergene may refer to:

• Supergene, a group of neighbouring genes on a chromosome that are inherited together because of close genetic linkage and are functionally related in an evolutionary sense
• Supergene (program), a computer program which allows the user to test a variety of plant genetics models
• Supergene (geology), in ore deposit geology, processes or enrichment occurring relatively near the surface, as opposed to deep hypogene processes