Abstract
ABSTRACTSex determination of Daphnia pulex is decided by environmental conditions. We established a suitable experimental system for this study using D. pulex WTN6 strain, in which the sex of the offspring can be controlled by photoperiod. Long-day conditions induced females and short-day conditions induced males. Using this system, we previously found that methy farnesoate (MF), which is a putative innate juvenile hormone molecule in daphnids, is necessary for male sex determination and that protein kinase C (PKC) is a candidate factor of male sex determiner. In this study, we demonstrated that a PKC inhibitor [bisindolylmaleimide IV (BIM)] application strongly suppressed male offspring induction in the short-day condition. Moreover, co-treatment of BIM with MF revealed that PKC signaling acts upstream of MF signaling for male sex determination. This is the first experimental evidence that PKC is involved in the male sex determination process associated with methyl farnesoate signaling in daphnid species.
Highlights
The micro-crustacean water flea, genus Daphnia, is a representative zooplankton in freshwater inland ecosystems
Based upon this induction system, we demonstrated that methyl farnesoate (MF) is likely an innate juvenile hormone (JH) in daphnids (Toyota et al, 2015a), and N-methyl-Daspartate (NMDA) receptors act as upstream regulators of MF signaling during male offspring production (Toyota et al, 2015b)
To investigate the involvement of protein kinase C (PKC) in male offspring production under short-day conditions in D. pulex, we compared the sex ratio of offspring produced by females under PKC inhibition to control conditions for both long-day and short-day environments
Summary
The micro-crustacean water flea, genus Daphnia, is a representative zooplankton in freshwater inland ecosystems. The sex ratio of a clutch of this strain can be controlled by changing the photoperiod; a mother produces female progeny under long-day conditions (14 h light:10 h dark), whereas male progeny exclusively emerge under the short-day conditions (10 h light:14 h dark) (Toyota et al, 2015a).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
