Gynogenetic

Gynogenetic describes organisms that reproduce by gynogenesis, a reproductive mode in which female eggs are activated by sperm but the paternal genome is not incorporated into the offspring. In gynogenesis, fertilization may occur to trigger development, but the paternal chromosomes are typically excluded or inactivated, yielding offspring that are genetically maternal clones. Mechanisms to restore diploidy can include duplication of the maternal genome or suppression of meiosis.

The best-known example occurs in fishes, notably the Amazon molly (Poecilia formosa), a diploid, all-female species that reproduces via gynogenesis and uses sperm from closely related species solely to activate eggs. Gynogenetic lineages have been observed in other fish groups and are studied for their unique mode of asexual reproduction and its evolutionary implications.

Genetically, gynogenetic offspring are usually maternal in origin. However, rare paternal leakage can occur, in which paternal DNA is retained or incorporated, introducing occasional genetic variation into otherwise clonal lineages. The study of gynogenesis helps illuminate the range of reproductive strategies, genome maintenance in asexual systems, and the evolutionary trade-offs between sexual and asexual reproduction.

See also: parthenogenesis, asexual reproduction, clonal reproduction.