FLPing around aids behavioural adaptability in nematodes

Nematodes are a success story in the Animal Kingdom and they are second only to the Arthropods in terms of numbers. The anatomy of a nematode is very simple - they only possess longitudinal muscles in their body wall and their nervous system comprises of ~300 nerve cells that are arranged in a similar pattern in species across the phylum. Despite this, they are complex, diverse and highly specialised animals. Indeed, one reason for their success is the diversity in their behaviour and their ability to survive in many different habitats throughout the world as both free-living and parasitic species. Nematodes can be divided into different clades based on their relatedness - the current train of thought is that there are five major clades (I-V). As parasites of livestock, nematodes can significantly impact the health and well-being of agricultural animals, thereby directly affecting productivity, economic return and animal welfare. For example, Haemonchus contortus is the most pathogenic nematode of sheep, leading to severe anaemia and sometimes death. As parasites of plants, nematodes can cause total destruction of plant material, and are a significant problem in many commercially important crops such as potato and tomato, amongst others. A key issue in the control of nematode parasites is that the drugs that are currently used to treat them are becoming less effective as the worms develop resistance. In fact, in some areas of the world (for example, parts of Scotland and New Zealand), sheep and cattle cannot be farmed simply because of parasite control problems. Therefore we need to search for novel drug targets so that livestock farming has a future both in the UK and further afield. In order to ensure survival a nematode must move, feed, and reproduce. Each of these behaviours rely on muscle, and are under the control of signalling molecules within the nervous system of the nematode. Unlike structure, the chemical make-up of the nematode nervous system is complex. One group of signalling molecules are the neuropeptides. In nematodes there are three main families of neuropeptides, the largest of which are known as the FMRFamide-like peptides or FLPs. FLPs have been shown to modulate feeding, reproduction and movement in many nematode species and therefore, the FLP signalling system is a potential novel drug target candidate. There are >70 FLPs in nematodes, and the same structures have been shown to be present in free-living and parasitic species. We don't know if these structures play similar roles in different nematode species. This information is important in order to select the 'best' candidates for drug targetting. For example, if an individual FLP was critical to the survival of one animal-parasite but not to another, then it would be a less attractive target than one that played an important role in several important nematode parasites. We have some preliminary evidence which points to functional differences in FLPs across the nematode phylum. This study plans to investigate the role of individual FLPs in nematodes by examining their distribution in the nervous system of a range of nematode species representing different clades and lifestyles and probing the effects of the FLPs on muscle-based behaviours. This research will increase our understanding of the FLP signalling system in nematodes, and comparative analyses will provide baseline data on the utility of FLP signalling as a target system for parasite control.

Parasitic nematodes impose a major economic and welfare burden on livestock, with global economic losses associated with animal death, reduced growth and productivity, in addition to the costs associated with anthelmintic treatment. Unfortunately, the current spectrum of drugs used to treat nematode parasites of livestock are compromised by resistance, compounding the economic impact. The nematode neuromuscular system has proved to be a rich source of drug targets, as it is responsible for governing many aspects of nematode behaviour that ensure survival. Indeed, most of the current broad spectrum anthelmintics target the classical transmitter component of this system, and yet the neuropeptidergic system is as important to the normal behaviour of the nematode parasite. Significantly, this system will not be burdened by resistance. A major hurdle to exploitation of the neuropeptidergic system is the lack of functional validation of neuropeptides and their receptors in key parasite species. In this study we will employ multiple techniques to investigate the function of the largest family of nematode neuropeptides, the FMRFamide-like peptides (FLPs), and its conservation throughout phylum Nematoda. We will combine recent technical advances in neuropeptidomics and quantitative PCR with classical localization methodologies (ICC, ISH) to probe FLP and FLP receptor expression in a range of nematode species. In addition, we will use reverse genetics (RNA interference, deletion mutants), and a mixture of simple bioassays with computational behavioural platforms to investigate FLP and FLP receptor function. This will provide us with information on whether or not FLPs and their receptors are functionally conserved in different nematode species from divergent habitats or clades, and it will allow us to identify those receptors to which novel therapeutics can be directed.

Parasitic helminths are a major threat to global food security, and have been estimated to cost the livestock industry worldwide more than $50 billion/annum. The treat-all application approach of broad-spectrum anthelmintics has been the primary method to control parasitic worms in livestock in the developed world for over 50 years, and has made the production of cheap and plentiful food to a growing world population feasible. New control strategies are urgently needed as anthelmintic resistance in nematode parasite populations is spreading globally, and this coupled to the restricted portfolio of new anthelmintics, means that in some parts of the world intensive livestock farming is not sustainable in the absence of new parasite control measures. The programme of research outlined in this proposal, through the discovery and validation of novel drug targets, will help inform industry, government and funding bodies about the potential of developing a more effective control strategy for parasitic worm diseases of livestock. The non-academic beneficiaries of this proposal will range from worldwide farming communities, who would benefit directly from the development of a novel chemotherapeutic for parasite control, to a range of pharmaceutical and biotechnology industries that will have the opportunity to further develop and/or commercialize new validated targets. The applicant (Mousley) has established connections with the Animal Health Industry via current and past research contracts and collaborations (Merial, Pfizer and Jansen Animal Health). Her contacts in these organisations would be in a position to advise on exploitation of the research findings. With respect to the reduction of anthelmintic use, the general public also demand safe, chemical residue reduced food, produced cost effectively from animals maintained in a welfare friendly environment, and therefore would benefit from a novel drug that required fewer applications. In addition, Levy bodies (including the Agriculture and Horticulture Development Board) and government will benefit from this applied research, which has the potential to shape future policy and strategy. The impact benefits of this programme will be revealed via website, media, public awareness events such as Science Weeks, Agricultural Shows and conferences. The UK applicant has experience in engaging the farming community through publications in Farming Journals and attendance at Agricultural shows. Public communication of our research in the UK will also be via stands, generic talks by research staff and academic staff at UCAS visits and Open Days to prospective students and parents in respective departments of the applicants. The integrated design of the programme and the questions being addressed should facilitate generation of at least one major headline publication with further impact capabilities. Publications from the research will be co-ordinated by Press and Public Relations Departments at QUB. In addition, the EU- and USA-based collaborators will further enhance international dissemination of the research findings worldwide.