Exploring the regulatory role of nitric oxide (NO) and the NO-p38MAPK/cGMP pathway in larval settlement of the bryozoan Bugula neritina

Abstract

The bryozoan Bugula neritina is a cosmopolitan marine fouling species that causes major fouling problems in sub-tropical waters. Settlement of B. neritina larvae can be triggered without an obvious external cue. Here, the negative regulatory role of nitric oxide (NO) during larval settlement of B. neritina was demonstrated to be mediated by cyclic guanosine monophosphate (cGMP). Although the regulatory role of the NO-p38 MAPK signaling axis in larval settlement was not evident, inhibition of nitric oxide synthase (NOS) led to the deactivation of p38 MAPK. Exclusive localization of NO and NO signaling components in sensory-related organs of the larvae is consistent with its signal transduction function in metamorphosis. Overall, this study provides new insights into the regulatory roles of the NO-p38MAPK/cGMP pathway in B. neritina settlement.

Keywords:

• Bugula neritina
• nitric oxide (NO)
• cGMP
• p38 MAPK
• larval settlement

Acknowledgements

The authors would like to thank Ms Yin Ki Tam, the technician at Coastal Marine Laboratory, HKUST, for her help with maintaining the research facilities.