Key Questions
To understand host generalist and specialist associations for avian malaria lineages that differentially infect two bird families in Australian and the South Pacific.
Background
Avian malaria is a cosmopolitan disease of birds caused by infection by Haemosporidian parasites (genera Haemoproteus and Plasmodium). There is a high diversity of genetic lineages within each genus, some of which are host generalists and others host specialists. Understanding the flexibility in host breadth is informative for understanding host switching, emergent disease associated with changing distributions (for example due to climate change or species introductions), and evolutionary phenomena such as taxon cycles. This project will use whole genome sequencing data generated from birds known to carry avian malaria infections to look for associations between host and parasite genomes
Aims of the Project
What is the extent of host family level specialisation of two clades of Haemoproteus
Is there a genomic basis to host family level specialisation
Project Description
Avian communities in Australia and the southwest Pacific coexist with a heterogeneous and diverse avian haemosporidian parasite community - vector-mediated parasites that cause avian malaria. Parasite biogeographic patterns and host associations indicate the distributions and prevalence of different parasite genera are influenced by different mechanisms, primarily geography and local island effects for Plasmodium spp., compared to host interactions for Haemoproteus spp. Further work has shown that multi-host haemosporidian parasites generally use hosts that are closely related, not hosts with similar habitat niches. This suggests that there may be intrinsic features of host species that allow them to combat infection by particular parasite lineages.
In southern Melanesia in the Pacific, two host bird families, the white-eyes (Zosteropidae) and honeyeaters (Meliphagidae) show contrasting infection patterns by the two main clades of Haemoproteus species, despite overlapping geographic distributions and habitat use by members of the two bird families. The honeyeater-infecting clade has not been recovered in any white-eyes despite extensive sampling. The white-eye infecting clade is only very rarely recovered in honeyeater hosts.
This primary aim of the project will apply whole genome sequencing to characterise the host and parasite genomes to ask if there is a genomic basis to family-level specialisation by the parasite clades. There will be opportunities for a student to take the project in various directions involving further genomic work, field work to extend host range sampling, or even exploring the potential for self-medication by honeyeaters that feed on plant species with anti-malarial compounds.
Methods to be used
Whole genome sequencing, population genomic analyses, phylogenetic analyses, potential for fieldwork (bird catching)
Specialised skills required
Bioinformatics training, genomics
Please contact Sonya Clegg on sonya.clegg@zoo.ox.ac.uk if you are interested in this project
Further reading:
Clark NJ, SM Clegg (2017) Integrating phylogenetic and ecological distances reveals new insights into parasite host specificity. Molecular Ecology 26: 3074-3086.
Clark NJ, K Wells, D Dimitrov, SM Clegg (2016) Co-infections and environmental conditions drive the distributions of blood parasites in wild birds. Journal of Animal Ecology 85:1461-1470.
Olsson-Pons, S, NJ Clark, F Ishtiaq, SM Clegg (2015) Differences in host species relationships and biogeographical influences produce contrasting patterns of prevalence, community composition and genetic structure in two genera of avian malaria parasite in southern Melanesia. Journal of Animal Ecology 84: 985-998
Fecchio A, K Wells, JA Bell, VV Tkach, HL Lutz, JD Weckstein, SM Clegg, NJ Clark (2019) Climate variation influences host specificity in avian malaria parasites. Ecology Letters 22:547-557.
