Project summary

The core interests of the Neptune ITN are the development and evolution of the nervous system, which has evolved millions of years ago in the ocean. To this end, we have studied several species that live in the sea, because they are most informative about the simple nervous systems that might have been present in ancient animals. Our special emphasis has been on investigating and comparing simple sensory systems, such as nose and eye. A deeper understanding of nervous system evolution is only possible in the broader context of body plan evolution. That means, to understand the structure and function of sensory organs and nervous systems we also need to study, compare and understand the development and evolution of the animals where these systems are active.

The network applied an evo-devo approach, where the development of early larval stages in different species is compared to infer the evolution of animals. For our comparative molecular study, we have chosen to work on new, emerging marine model organisms, since life emerged from the sea. For these species, we attempted to establish the most modern techniques available for molecular biology, such as genetic engineering with a bacterial system that cuts DNA at predefined sites (Crispr-Cas9), and state-of-the-art microscopy, such as the newly developed light sheet microscopy. Our experimental work then focused on describing the form, architecture, and function of different planktonic animals living in the sea, and of their simple sense organs and nervous systems, at several developmental and life cycle stages. We even managed to study the behavior of these tiny animals. Since evolution can only be fully understood if one also studies the existing remnants of previous life forms, we also included paleontological studies into our collaborative network activities.

The perception of light is key to almost all animal behavior, such as locomotion, feeding, but also the timing of reproduction. This is why light-sensitive molecules and cells (called photoreceptors) and eyes have evolved in many different variants. Exemplifying this, one of the Neptune fellows has studied the photoreceptors that trigger spawning in a jellyfish. Other fellows have studied the proteins taking part in light detection, and the photoreceptors, in the planktonic larvae of different species, ranging from the small crustacean Parhyale, or the marine annelid Malacoceros, to the planktonic larvae of a sea urchin and flatworms. These photoreceptors play a role in the control of ciliary swimming towards the light and during day and night. Since the perception of chemicals is also important for guiding larval behavior, another fellow has studied the chemical-detecting cells of a planktonic annelid and the odors they perceive. Finally, several fellows have studied neuropeptides, larval hormones acting downstream of the sensory stimuli to drive behavior – in the context of larval vision but also of spawning control.

The Neptune network have been truly multidisciplinary, including also a large company such as Zeiss that provided for advanced microscopy training, as well as R&D training. We have also organized a variety of training events: the practical summer courses of the series Marine Animal Models in Evolution and Development, have focused on topics such as nervous system and behavior, advanced light microscopy, functional interference and bioinformatics. In addition, we organized a Graduate School once every year, in order to give the fellows time to discuss in depth their projects with their peers and the PIs of the network. The Neptune mentoring programme (with each student chosing a mentor among the PIs of the network and meeting at least once a year) has been a clear success.
One important novelty of our ITN has been the recruitment of short-term fellows for nine to twelve month. These were graduate students who wanted to work on a short-term project to refine their interests and to learn specific techniques. All of these fellows integrated well into the network and also attended training events. Some have meanwhile embarked in a full PhD in the hosting Neptune laboratory.

The Neptune ITN has successfully involved external visiting scientists in the organization of the Summer Courses. This enriched the scientific horizon and allowed the fellows to establish international contacts that have already proven useful for the fellows’ careers.

During the training events, the fellows also trained their soft skills, to advance their careers. Fellows participated in a ‘Communicating Evolution Day’, taught by the Director of the National Centre for Science Education in the USA, Dr. Eugene Scott. They also attended seminars and workshops on scientific writing, science communication, intellectual property, editorial work for a scientific publisher, and scientific project management. Most important,
The Neptune fellows successfully organized a final conference, the Neptune Evo-Devo Symposium, which was held at the University of Lisbon in November 2016. This event welcomed about 60 participants and 10 invited speakers from outside the network. On this occasion, all Neptune fellows presented their work either on a poster, or with a presentation, allowing them to share and discuss their results with a broad scientific audience –  including some of the major experts in the evo-devo field. For the fellows, the organization of the symposium was the culprit of their Neptune experience and, at the same time, the platform for preparing the next steps in their career.