Nematode genetics,
genomics and phylogenetics
Dr. M. Blaxter
Nematode diversity and
evolution
The phylum Nematoda is an
important component of life on Earth, yet surprisingly little work has been
done so far on the origins and relationships of the very diverse species. We
are particularly interested in the origin and evolution of the parasitic
nematodes, including insect, vertebrate and plant parasites. Projects are
available looking at a range of parasitic groups, including the major nematode
parasites of humans. We are also involved in an extensive survey of nematode
biodiversity in Scottish soils and coastal habitats, and are examining the
correspondances between morphological, biological and molecularly-defined
"species".
Parasitic nematode genomics
We are using the tools of
genomics to analyse gene expression in a number of nematodes parasitic in
humans and our domestic animals. The recent determination of the complete
genome sequence of Caenorhabditis elegans offers opportunities to examine
issues of conservation of synteny, the functional significance of gene order,
the molecular biology of gene expression (in particular trans-splicing) and the
structural biology of nematode genes. We are involved in a search for novel
parasitism-specific genes that might be drug target or vaccine component
candidates to alleviate human disease. We offer projects in comparative
genomics of nematodes, and functional analysis of gene organisation in
parasites. See http://www.nematodes.org for a summary of our work and
opportunities/projects available.
Analysis of nematode gene
function using Caenorhabditis elegans
C. elegans is an easily
manipulated free living nematode. We use forward and reverse genetics
approaches to study selected genes and processes that may be important for the
survival of parasitic species. Projects on offer focus on the cuticle, in
particular the biosynthetic enzymes involved in constructing this resilient
outer layer.
Back to postgrad opportunities
Genetic variation in
Scottish red deer
Dr J Pemberton CV and research interests
The red deer is Britain's
largest land animal and a named subspecies (Cervus elaphus scoticus).
Unfortunately, the population has been subject to many introductions from other
populations in Europe and related taxa with which it will hybridise, such as
Japanese sika deer (Cervus nippon) and North Amercian wapiti (Cervus
canadensis). Using samples from throughout Scotland and from putative source
populations, and building on work already undertaken on sika introgression, the
project will use genetic markers (microsatellites and mtDNA) to address
questions such as the following:
- How much genetic differentiation is there
between Scottish red deer populations?
- Can the genetic influence of introduced
deer be detected, and if so,
- Where, in Scotland, are the red deer least
affected by these introductions?
The project will train the
student in molecular genetic methods and statistical analysis of population
genetic data.
References
Goodman, S J, Barton N H,
Swanson G, Abernethy K & Pemberton J M (1999) Introgression through rare
hybridisation: a genetic study of a hybrid zone between red and sika deer (genus
Cervus), in Argyll, Scotland. Genetics 152: 355-371.
Slate J, Kruuk L E B,
Marshall T C, Pemberton J M and Clutton-Brock T H 2000 Inbreeding depression
influences lifetime breeding success in a wild population of red deer (Cervus
elaphus). Proceedings of the Royal Society of London, B. 267:1757-1662.
Parasite diversity and
host resistance in unmanaged sheep
In the
individually-monitored Soay sheep of St. Kilda, parasite resistance (measured
as strongyle faecal egg count, FEC) varies with the level of inbreeding of the
host and with genotype at certain loci, for example in the MHC. One possible
mechanism underlying these observations is that these host factors reflect an
ability to resist different species or genotypes of parasite - for example,
inbred hosts may not be able to resist as many different species or genotypes
of parasites as outbred hosts. The project will investigate parasite diversity
in greater detail than hitherto by (1) analysing existing data, which separates
parasites into crude taxonomic categories (2) classifying parasite diversity
further, in terms of taxa, than is currently done and (3) investigating genetic
variation (probably using microsatellites) within the commonest parasite
species, Teladorsagia circumcincta. The project will be collaborative with
other members of the St. Kilda Soay sheep project and ICAPB, and will train the
student in parasitology techniques, molecular genetics and statistical analysis
of complex data.
References
Coltman D W, Pilkington J
G, Smith J A and Pemberton J M (1999) Parasite-mediated selection against
inbred Soay sheep in a free-living island population. Evolution 53:1259-1267.
Paterson S,
Wilson K and Pemberton J M (1998) Major histocompatability complex (MHC)
variation associated with juvenile survival and parasite resistance in a large
unmanaged ungulate population (Ovis aries L.) Proc. Natl. Acad. Sci. USA.
95:3714-3719.