Clonal reproduction by males and females in the little fire ant

Abstract

Sexual reproduction can lead to major conflicts between sexes and within genomes. Here we report an extreme case of such conflicts in the little fire ant Wasmannia auropunctata. We found that sterile workers are produced by normal sexual reproduction, whereas daughter queens are invariably clonally produced. Because males usually develop from unfertilized maternal eggs in ants and other haplodiploid species, they normally achieve direct fitness only through diploid female offspring. Hence, although the clonal production of queens increases the queen's relatedness to reproductive daughters, it potentially reduces male reproductive success to zero. In an apparent response to this conflict between sexes, genetic analyses reveal that males reproduce clonally, most likely by eliminating the maternal half of the genome in diploid eggs. As a result, all sons have nuclear genomes identical to those of their father. The obligate clonal production of males and queens from individuals of the same sex effectively results in a complete separation of the male and female gene pools. These findings show that the haplodiploid sex-determination system provides grounds for the evolution of extraordinary genetic systems and new types of sexual conflict.

Population genetic structure, worker reproduction and thelytokous parthenogenesis in the desert ant Cataglyphis sabulosa

“…It has been suggested that the conditional use of parthenogenesis for new queen production would primarily occur in dependent-founding species, because the presence of workers compensates for the negative effects of increased inbreeding on founding queens due to thelytoky (Pearcy et al, 2004a). In line with this prediction, the production of female sexuals by queens through thelytokous parthenogenesis has been reported in three ant species with a dependent mode of colony foundation: the monogynous ant C. cursor, and two polygynous species, Wasmannia auropunctata (Fournier et al, 2005) and Vollenhovia emeryi (Ohkawara et al, 2006). As mentioned earlier, our genetic analyses confirm that colony reproduction in C. sabulosa proceeds through flight dispersal and independent colony founding.…”

Cheating honeybee workers produce royal offspring

“…Clonal reproduction of offspring-queens has been previously reported in two species of ant, the little fire ant Wasmannia auropunctata ( Fournier et al 2005) and Cataglyphis cursor (Pearcy et al 2004). In both ant species, queens are produced predominantly asexually while workers are always produced sexually.…”

Simultaneous Mendelian and clonal genome transmission in a sexually reproducing, all-triploid vertebrate

“…Some animal genomes, however, display transmission biases, often according to parent of origin, and usually as a consequence of ancient hybridization [2]. Hybrid lineages of ants, for instance, carry two independently evolving genomes, which are transmitted either meiotically [3] or clonally [4,5]. Similar processes occur in hybridogenetic vertebrates: in diploid hybridogenesis, one genome is transmitted clonally through the hybrid lineage, while the other is transmitted sexually by one of its parental species [6].…”