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In so-called unisexual teleost fishes, a broad spectrum of evolutionaty stages with varying amounts of sexual elements has evolved. These range from pure sperm-dependent parthenogenesis (gynogenesis) without or with different amounts of paternal leakage to hybridogenesis with hemiclonal diploid gametogenesis or genome elimination folowed by meiosis (meiotic hybridogenesis). All of these phenomena are hybrid origin. Many of these fish form complexes which involve the coexistence of one or more sexually reproducing species with derived all-female forms that have various ploidy levels and reproductive modes, including gynogenesis, (meiotic) hybridogenesis nnd sexual reproduction. In teleosts, parthenogenetic reproduction is strictly dependent on sperm to initate embryonic development. As opposed to true parthenogenesis, sperm-dependent parthenogenetic teleost lineages must primarily coexist with their "sperm donor", usually males from a parental sexual lineage or from a related sexual species. In some systems, gynogens were able to escape from their initial sperm donors ("host switch") and therefore, to enlarge their ranges and ecological niches. Sperm donors normally do not contribue genetically to the next generation. However, paternal leakage is observed in many systems contributing differing amounts of genetic material (from microchromosomes to entire chromosome sets) allowing interaction between genomes of different origin. Hybridogenesis is similar to gynogenesis in depending upon coexisence with sexual species but incorporates recombined genetic material by true fertilizazion. While hybridogens usually form clonal gametes, some triploids are capable of genome elimination followed by a normal diploid meiosis. Sperm-dependent parthenogenesis and hybridogenesis combine disadvantages and advantages from both sexuality and asexuality. Here, we give an overview of sperm-dependent breeding complexes in fishes, discuss the evolutionary consequences of paternal leakage, and speculate about the evolutionary significance of intergenomic (re)combination.

[9/7/19, rond-point des Champs-Élysées, canons allemands entassés pour les préparatifs de la Victoire] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 54807

8-8-19, Deauville [enfants jouant dans l'eau] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 55362

8-8-19, Deauville [nombreux baigneurs] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 55363

8-8-19, Deauville [bain de mer familial] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 55383

8-8-19, Deauville [bain de mer familial] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 55382

8-8-19, Deauville [bain de mer familial] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 55381

8-8-19, Deauville [groupe de baigneurs] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 55370

8-8-19, Deauville [bord de mer, loisirs estivaux] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 55367

10-8-19, Deauville [promeneurs] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 55420

10-8-19, Deauville [épreuve sportive pour garçonnets sur la plage devant le casino] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 55417

10-8-19, Deauville, [Jacques] Keyser [coureur à pied] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 55416

10-8-19, Colombes, arrivée du championnat de france du 800 m [Jean Vermeulen vainqueur] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 55412

[9/7/19, rond-point des Champs-Élysées, canons allemands entassés pour les préparatifs de la Victoire] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 54808

Départ du [prix] Gondrand [course de relais facultatifs par équipe de trois], Colombes, 9/11/19 : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 56840