Little is known regarding sex determination mechanisms in Hymenoptera. However, sl-CSD, one of the main proposed mechanism could drive small populations into a vortex of extinction. Indeed, this mechanism relies on a single locus (namedcsd), only individuals heterozygous at this locus developing into females while homozygous individuals develop into diploid males of reduced fitness. Thecsdgene has been identified in the honeybee and was considered to be unique to the Apis lineage. Our results have demonstrated that i)csdis not restricted to the Apidae but is also present in bumblebees and ants genome, ii) csd originates from an ancestral duplication of thefemgene (key gene in sex determination) in the ancestor of the sub-orderAculeata, iii) thefemandcsdgenes are one of the rare examples of concerted evolution based on gene conversion. These results raise the question of the occurrence and possible role of thecsdgene in other Hymenoptera, notably in parasitoid wasps, largely used in biological control.
- Schmieder S, Colinet D, Poirié M (2012) Tracing back the nascence of a new sex determination pathway to the ancestor of bees and ants. Nature Communications 3: 895