Interspecific Hybridization and the Evolutionary Origin of a Gynogenetic Fish, Poecilia formosa

Population genomics reveals a possible history of backcrossing and recombination in the gynogenetic fish Poecilia formosa.

Unisexual sperm-dependent vertebrates are of hybrid origins, rare, and predicted to be short-lived as a result of several challenges arising from their mode of reproduction. In particular, because of a lack of recombination, clonal species are predicted to have a low potential to respond to natural selection. However, many unisexual sperm-dependent species persist, and assessing the genetic div...

Electrophoretic Demonstration of the Hybrid Origin of the Gynogenetic Teleost Poecilia formosa

Stable inheritance of host species-derived microchromosomes in the gynogenetic fish Poecilia formosa.

B chromosomes are additional, usually unstable constituents of the genome of many organisms. Their origin, however, is often unclear and their evolutionary relevance is not well understood. They may range from being deleterious to neutral or even beneficial. We have followed the genetic fate of B chromosomes in the asexual, all-female fish Poecilia formosa over eight generations. In this specie...

The origin and evolution of a unisexual hybrid: Poecilia formosa.

Clonal reproduction in vertebrates can always be traced back to hybridization events as all known unisexual vertebrates are hybrids between recognized species or genetically defined races. Interestingly, clonal vertebrates often also rely on interspecific matings for their reproduction because gynogenesis (sperm-dependent parthenogenesis) and hybridogenesis are common modes of propagation. Whil...

Hybridization leads to sensory repertoire expansion in a gynogenetic fish, the Amazon molly (poecilia formosa): a test of the hybrid-sensory expansion hypothesis.

Expansions in sensory systems usually require processes such as gene duplication and divergence, and thus evolve slowly. We evaluate a novel mechanism leading to rapid sensory repertoire expansion: hybrid-sensory expansion (HSE). HSE occurs when two species with differently tuned sensory systems form a hybrid, bringing together alleles from each of the parental species. In one generation, a sen...