Which
resources are necessary to address the key questions about the Evolution
of Development?
Genomic
information on representative organisms distributed over the ToL
The
First 100 - Jump Starting the Field
The importance
of the robust phylogenies being pursued by ToL efforts was emphasized.
In concert with this information, the most pressing need for the Evo-Devo
community is to have access to genomic information on a wide range of
organisms. A major initiative in Evo-Devo must be jump-started with
the creation of BAC and cDNA libraries for 100 key taxa. This cast of
100 should represent the major trunks of the tree with broad synoptic
coverage related to the major Evo-Devo questions. Some key taxa have
already been fully sequenced and the First 100 will not duplicate this
effort. It is essential that this initial group of organisms show some
promise of being tractable in the lab. That is, specimen access and
propagation need to be considered. A funding competition for groups
to create these libraries will necessarily bring together the Evo-Devo
and ToL communities in a synergistic way. The actual selection of the
First 100 will be community driven. Peer review will ensure broad taxonomic
coverage.
The First 100
and all subsequent organismal libraries need to be shared readily with
the community and centralized repository and distribution centers are
essential. The competition for the First 100 grants should result in
genomic museums with the capability to
catalog and distribute arrayed BAC and pooled cDNA libraries.
These centers
should also be prepared to become repositories and distribution centers
for fully- sequenced genomes, ESTs, cDNAs and additional BACs that will
be completed in later phases of the Evo-Devo Initiative. There is definitely
economy in subcontracting the construction of libraries and genomic
museums should be encouraged to pursue this. Genomic museums will have
tremendous value for both Evo-Devo and ToL community members, as well
as any biologist interested in comparative molecular studies. Quality
control is absolutely essential and the First 100 will not only provide
an immediate and much needed resource, but will also establish an infrastructure
for library deposition and distribution that is incredibly reliable
and reproducible.
The informatics
component of this effort is equally important. A dispersed model appears
most efficacious and would be a joint effort between the Evo-Devo and
ToL communities. ToL has solidly begun building a phyloinformatics infrastructure.
Coalesced with data coming from Evo-Devo efforts this should provide
a rich resource for a large component of the biological community. Informatics
data must have user access that is transparent. All informatics (both
from the genomics and phylogenetics perspective) must be vouchered.
Phylogenetic data coupled with genomic and developmental data coming
from the Evo-Devo community should be preserved in digital form for
long lasting research and educational impact. The databases must be
relational or object oriented. The initial investment in the infrastructure
of this accessible resource is critical to both communities and will
facilitate synergistic interactions. The NSF-supported Drosophila
stock and information center is an example that should be considered
in developing the informatics infrastructure.
Sequencing
Major Developmental Gene Families in the First 100
ToL is beginning
to integrate nuclear genome sequences into phylogenies and the participants
explored the need and rationale for using developmentally significant
genes in these trees. There are just a few dozen gene families in the
developmental modules/cassettes in organisms investigated to date (e.g.,
Table 1). Sequencing homologous families in the First 100 organisms
will be invaluable in addressing many Evo-Devo questions. It would be
particularly interesting to find if some organisms lack certain modules
and if they have evolved alternative strategies. This resource should
be particularly helpful for the ToL community as they move towards using
nuclear genes in phylogenetic analysis since these genes have central
roles in development. Some of this sequencing may be very important
in resolving uncertainties at important nodes in the Tree of Life. A
discussion among phylogeneticists and developmental geneticists revealed
how much they can learn from each other. For example, many of the highly
conserved motifs in these major gene families are coupled with rapidly
evolving neighboring sequences. This is a conceptual challenge in phylogenetic
tree construction and is of fundamental mechanistic interest to Evo-Devo
researchers. There are resolution challenges in dealing with families
of genes in phylogenetic construction. This sequencing project would
be valuable one for the ToL community to undertake and would facilitate
community building between Evo-Devo and ToL researchers.
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