Genetic variation and asexual reproduction in the facultatively parthenogenetic cockroach Nauphoeta cinerea: implications for the evolution of sex

摘要: Asexual reproduction could offer up to a two-fold fitness advantage over sexual reproduction, yet higher organisms usually reproduce sexually. Even in facultatively parthenogenetic species, where both and asexual is sometimes possible, rare. Thus, the debate evolution of sex has focused on ecological mutation-elimination advantages sex. An alternative explanation for predominance that it difficult an organism accomplish once evolved. Difficulty returning asexuality reflect developmental or genetic constraints. Here, we investigate role factors limiting Nauphoeta cinerea, African cockroach with facultative parthenogenesis nearly always reproduces We show when N. cinerea females do asexually, offspring are genetically identical their mothers. However, limited nonrandom subset genotypes population. Only have high level heterozygosity capable there strong familial influence ability parthenogenetically. Although mechanism by which variation facilitates unknown, suggest heterosis may facilitate switch from producing haploid meiotic eggs diploid, essentially mitotic, eggs.