TABLE CONTENTS

SESSION FORTY-FOUR – GENE KNOCK-DOWN APPROACHES IN
NEMATODE RESEARCH
CONVENORS: GODELIEVE GHEYSEN & RALF SOMMER
Genetic and Transgenic Approaches in the Nematode Model Pristionchus
pacificus
Sommer, R.J.
Max-Planck Institute for Developmental Biology, Tübingen, Germany
Pristionchus pacificus has been established as a model system in evolutionary biology, in
particular in evolutionary developmental biology (evo-devo). P. pacificus shares with
Caenorhabditis elegansmany technical features starting form self-fertilizing propagation with
the spontaneous generation of males, which allows the use of forward genetic technology.
Under laboratory conditions, the life cycle of P. pacificus is 3-4 days (20° C) on Escherichia
coli as food source. The genome of P. pacificus has recently been sequenced and is
substantially larger than the one of C. elegans or Brugia malayi. Because studies on the
regulation of vulva development revealed many important differences between P. pacificus
and C. elegans, we have started to establish a comprehensive tool kit for functional studies in
these nematodes. In the talk, I will provide an overview on the state of reverse genetics by
RNAi and morpholino studies, forward genetics, genomics and DNA-mediated
transformation.
Gene Silencing and Neuromuscular Signalling in Plant Parasitic
Nematodes (PPNs)
Dalzell, J.J. (1,2), S. McMaster (1,2), M.J.G. Johnston (1,2), C.C. Fleming (2) &
A.G. Maule (1)
(1) Parasitology, School of Biological Sciences, Queen’s University Belfast, 97 Lisburn Road, Belfast BT9
7BL, UK; (2) Pest Molecular Biology Group, Newforge Lane, Agri-Food Biosciences Institute, Belfast, BT9
5PX, UK.
PPNs represent a serious threat to sustainable crops, accounting for more than $US 150
billion in annual agricultural loss worldwide. We have discovered that neuronally-expressed
genes in both Meloidogyne incognita and Globodera pallida infective juveniles (J2s) are
particularly susceptible to RNAi, and that silencing can be induced through simple soaking
procedures, resulting in the profound inhibition of nematode motility. One class of these
neuronal targets is the FMRFamide-like peptides (FLPs), a large family of neuropeptides
intimately involved in the control and regulation of neuromuscular function; unusually
diverse and abundant in the phylum Nematoda. Many of the drugs used to control nematode
parasites do so through disruption of neuromuscular function, and as the neuropeptide
complement is extraordinarily enriched, and conserved among nematodes, we argue that
neuronal signalling processes harbour significant potential as targets for novel in planta
control strategies. However, as specificity concerns become realized in a range of model
organisms, we now demonstrate an atypical response to dsRNA in a plant parasitic nematode
for the first time. Negative control dsRNAs, that shared no significant regions of homology
with identifiable nematode targets, were created from a range of plant, and non-plant-derived
constructs, and used to soak the worms. Although the control dsRNAs had no observable
affect on G. pallida J2 behaviour, they induced significant phenotypic changes in M.
incognita J2s.
5 th International Congress of Nematology, 2008 162