Metabolomics reveals an involvement of pantothenate for male production responding to the short-day stimulus in the water flea, Daphnia pulex

ABSTRACT: Under favorable conditions, the micro-crustacean Daphnia pulex produces female offspring by parthenogenesis, whereas in response to various unfavorable external cues, they produce male offspring to induce sexual reproduction (environmental sex determination: ESD). We recently established a suitable experimental system for ESD studies using D. pulex WTN6 strain, in which the sex of the offspring can be regulated simply by alterations in day-length; long-day and short-day conditions can induce female and male offspring respectively. Taking advantage of this system, we have already demonstrated that methyl farnesoate (MF) synthesis is necessary for male offspring production. Further, we identified ionotropic glutamate receptors as an upstream regulator of MF signaling by transcriptome analysis. Despite these findings, the molecular mechanisms associated with MF signaling have not yet been well elucidated in D. pulex. To more comprehensively understand the molecular mechanisms of ESD, we analyzed the whole metabolic profiles of mother daphniids reared under long-day (female-producing) and short-day (male-producing) conditions using mass spectrometry based metabolomics. We discovered that pantothenate (vitamin B5), a known precursor to coenzyme A, was significantly accumulated in response to the short-day condition. To confirm the role of pantothenate in D. pulex ESD, this metabolite was administered to mother daphniids (under long-day conditions) resulting in a significantly increased proportion of male offspring producing mothers. This study not only provides several candidates for further investigations into the molecular changes involved in male offspring production, but also novel insights into the metabolic mechanisms of the ESD system in D. pulex.

INSTRUMENT(S): LTQ FT-Ultra (Thermo Scientific)

SUBMITTER: Alex Gavin 

PROVIDER: MTBLS259 | MetaboLights | 2017-04-03

REPOSITORIES: MetaboLights