Laboratory generation of new Artemia parthenogenetic lineages through contagious parthenogenesis
Contagious parthenogenesis – a process involving rare functional males produced by a parthenogenetic lineage, which mate with coexisting sexual females resulting in fertile parthenogenetic offspring – is one of the most striking mechanisms responsible for the generation of new parthenogenetic lineages. Populations of the parthenogenetic diploid brine shrimp Artemia produce fully functional males in low proportions. The evolutionary role of these so-called Artemia rare males is, however, unknown. Here we investigate whether new parthenogenetic clones could be obtained in the laboratory through contagious origin. We assessed the survival and sex ratio of the hybrid ovoviviparous offspring from previous crosses between rare males and females from all Asiatic sexual species, carried out cross-mating experiments between F1 hybrid individuals to assess their fertility, and estimated the viability and the reproductive mode of the resulting F2 offspring. Molecular analysis confirmed the parentage of hybrid parthenogenetic F2. Our study documents the first synthesis of parthenogenetic lineages through contagious parthenogenesis in Artemia. We discuss the possible genetic mechanisms responsible for parthenogenesis and the likelihood of contagious parthenogenesis in natural environments.