along with the background and rationale for its fish model,
the services provided are discussed, and information given
on points of contact and web sites.
THE FUGU GENOMICS GROUP, HGMP
RESOURCE CENTRE, WELLCOME GENOME
CAMPUS, HINXTON, CAMBRIDGE, UK
Program Description
Hinegardner (1968) assayed the haploid DNA content of a
large number of teleosts and found that many species had
small genomes, especially the tetraodontoid (four-toothed)
fishes, which include the puffers. In Japan, the puffer fish
(Fugu rubripes) is a gastronomic delicacy that contains a
potent visceral neurotoxin that kills several people each
year. Estimates of the DNA content of Fugu indicate that its
genome size lies between 4 and 500 Mb (Hinegardner,
1968). However, this species should be viewed as a model
genome, not as a model organism, as experimentation on
Fugu is difficult. It grows to a kilogram within the first year,
becomes sexually mature in three years, and is difficult to
maintain using traditional methods.
The Fugu genome has about the same number of genes
as many mammalian genomes but the genes generally are
smaller (Clark and Elgar, 2000). Although coding sequences
are about the same size, intron sizes are greatly reduced,
intergenic distances are much smaller, and there is little
repetitive DNA, virtually none of which is dispersed (Bren-
ner, 1993; Edwards et al., 1998; Elgar et al., 1995). Hence,
cloning by PCR of all possible members of a particular gene
family (Macrae and Brenner, 1995: Venkatesh et al., 1996;
Cottage et al., 1999) is much easier in such a compact
genome as that of Fugu.
Due to the large evolutionary distance between mam-
mals and Fugu (approximately 400 Myr), conserved non-
coding elements presumably have a high probability of
functional significance, and so provide a minimal data set
with which to study promoter and regulatory elements
(Marshall et al., 1994; Aparicio et al., 1995; Venkatesh et al.,
1997; Rowitch et al., 1998). The extent of synteny between
Fugu and humans is questionable, with examples of com-
plete conservation of gene content, order, and orientation
(Miles et al., 1998), altered gene order (Gellner and Bren-
ner, 1999), and extensive rearrangements (Gilley and Fried,
1999). This variable syntechnic situation should not be dis-
missed as too confusing to explain. Closer examination of
particular regions of the genome, such as the MHC class I
region, can provide clues to the pattern of evolution of the
vertebrate genome (Clark et al., 2000). The complete geno-
mic sequence of both Fugu and humans will provide an-
swers to the question of synteny and produce copious data
for evolutionary geneticists. Four-way comparisons of ge-
nomic sequences among humans and some fishes, includ-
ing zebrafish, Fugu, and the freshwater puffer fish (Tetra-
odon nigroviridis), will give us a generalized picture of the
size of homologous gene blocks shared by mammals and
fish. Additionally, comparisons restricted to these three fish
species also will indicate the extent of conservation of syn-
teny within them, which will be of great interest for posi-
tional cloning studies in other fishes, particularly for re-
search on resistance and susceptibility to disease.
The Fugu Genomics Group, HGMP Resource Centre,
in Cambridge, seeks to demonstrate the advantages of using
the Japanese puffer fish (Fugu rubripes) as a model for in-
terpreting and analyzing vertebrate genomic data, with spe-
cial reference to the Human Genome Project. The group
also offers Fugu genomic resources free to the research com-
munity. The group is part of a consortium led by the Joint
Genome Institute (JGI) of the US Department of Energy to
sequence the Fugu genome. JGIs aim is to completely se-
quence the Fugu genome by using the shotgun sequencing
approach and to make the draft sequence data publicly
available in 2001. All sequence data will be posted on the
JGI web site (http://www.jgi.doe.gov). Having data on the
full genomic sequence will clearly alter the direction of the
research of the genomics group; the initiation of an EST
program will facilitate a move toward functional analyses.
Currently, scientists in the group are particularly interested
in three regions in the Fugu genome comparable to human
chromosomes 11p, 20q, and 6p21.3 (the major histocom-
patibility complex). Their other interests include G-protein
coupled receptors, conserved noncoding regulatory ele-
ments, and gene evolution and duplication in fish.
Services
The services and products offered from the Distributed
Services Group at the HGMP include the following: (1) a
cosmid library of 75,000 clones with an average insert size of
40 kb, equivalent to 7× genome coverage, available as grid-
ded filter sets; (2) high-molecular-weight Fugu genomic
DNA for Southern blots or PCR in 50-µg aliquots in TE
buffer and agarose plugs for constructing PFGE/libraries;
and (3) nonnormalized cDNA libraries, available as gridded
S240
William E. Hawkins et al.
Next >>