Parthenogenesis in amphibians

Parthenogenesis is a form of reproduction where eggs develop without fertilization, resulting in unisexual species.

This phenomenon is closely related with reproductive modes such as hybridogenesis, where fertilization occurs, but the paternal DNA is not passed on.

Oscar Hertwig first achieved artificial parthenogenesis in frogs in 1911, using eggs fertilized by irradiated sperm.

[2] Rana japonica, Pelophylax nigromaculatus and Lithobates pipiens have all produced viable haploid adults as a result of artificial parthenogenesis.

[4] In unisexual salamanders these different levels of polyploidy are a result of multiple hybridization events, involving two to four species.

[9] Most Ambystoma hybrids are described by how many haploid sets of chromosomes they contain from each of their parent species, reflecting their level of ploidy.

[13] Unisexual female mole salamanders of the genus Ambystoma are frequent in the region of the North American Great Lakes.

[15] The unisexual female Ambystoma can sometimes undergo genome exchange with males from sympatric sexual species.

[8] It has been documented in the European water frog complex of the genus Pelophylax, which includes three hybridogenic forms.

[8] In this reproductive mode unisexual females mate with sympatric males of related species, and genetic material in the paternal line recombines with the maternal DNA and thus is passed on.