Description:
<jats:title>Abstract</jats:title><jats:p>Males of all species of the parasitic wasp genus <jats:italic>Nasonia</jats:italic> use (4<jats:italic>R</jats:italic>,5<jats:italic>S</jats:italic>)-5-hydroxy-4-decanolide (<jats:italic>RS</jats:italic>) as component of their sex pheromone while only <jats:italic>N. vitripennis</jats:italic> (<jats:italic>Nv</jats:italic>), employs additionally (4<jats:italic>R</jats:italic>,5<jats:italic>R</jats:italic>)-5-hydroxy-4-decanolide (<jats:italic>RR</jats:italic>). Three genes coding for the NAD<jats:sup>+</jats:sup>-dependent short-chain dehydrogenases/reductases (SDRs) NV10127, NV10128, and NV10129 are linked to the ability of <jats:italic>Nv</jats:italic> to produce <jats:italic>RR</jats:italic>. Here we show by assaying recombinant enzymes that SDRs from both <jats:italic>Nv</jats:italic> and <jats:italic>N. giraulti</jats:italic> (<jats:italic>Ng</jats:italic>), the latter a species with only <jats:italic>RS</jats:italic> in the pheromone, epimerise <jats:italic>RS</jats:italic> into <jats:italic>RR</jats:italic> and <jats:italic>vice versa</jats:italic> with (4<jats:italic>R</jats:italic>)-5-oxo-4-decanolide as an intermediate. <jats:italic>Nv</jats:italic>-derived SDR orthologues generally had higher epimerisation rates, which were also influenced by NAD<jats:sup>+</jats:sup> availability. Semiquantitative protein analyses of the pheromone glands by tandem mass spectrometry revealed that NV10127 as well as NV10128 and/or NV10129 were more abundant in <jats:italic>Nv</jats:italic> compared to <jats:italic>Ng</jats:italic>. We conclude that the interplay of differential expression patterns and SDR epimerisation rates on the ancestral pheromone component <jats:italic>RS</jats:italic> accounts for the evolution of a novel pheromone phenotype in <jats:italic>Nv</jats:italic>.</jats:p>