Resource
Development for Termite Genomics
Srini
Kambhampati, Entomology
Project
Summary
Termites (Isoptera) are hemimetabolous eusocial insects that live in complex
societies.
Termites exhibit eusociality not unlike that found in ants and some bees and
wasps: caste
system, polyphenisms, multiple developmental pathways, complex communication,
symbiosis
with protozoans and bacteria, construction and maintenance of complex nests, and
use of
“agriculture.” Whereas kin selection explains the maintenance of eusociality in
haplodiploid
Hymenoptera a comparable theory for termites, in which both sexes are diploid,
is not
available. Since all extant termites are eusocial comparisons between non-eusocial
and eusocial
taxa are not possible. Finally, termites differ in substantial ways from honey
bees. Therefore,
genomic studies on termites are one of the few avenues left to obtain
information on the genetic
basis of cooperation and social living and lead to comparative studies with
evolutionarily
divergent honey bees, ants, and social wasps. Here, I outline a research plan to
develop
genomic resources that will set the stage for sequencing of a termite genome.
The specific
aims are: 1. Construct a BAC library from the termite Reticulitermes flavipes to
8X-10X coverage.
2. Sequence 10 randomly chosen BAC clones to obtain an initial characterization
of the R.
flavipes genome. The genome size of R. flavipes using flowcytometry was
estimated to be 1.03 Gb
distributed in 42 chromosomes. This research plan is complementary to an EST
project currently
in progress in the PI’s laboratory. We have constructed 5 cDNA libraries from R.
flavipes:
workers, soldiers, alates, larval stages 1-2, and larval stages 3-4; three more
libraries are
planned. We have sequenced ~2,000 ESTs and ~7,800 clones have been sent for
sequencing. We
plan to sequence an additional 12,000 ESTs in the next few months from the new
and existing
cDNA libraries. A consortium of termite researchers has been assembled to
collaboratively and
synergistically utilize the BAC and EST resources. These resources are expected
to significantly
enhance the viability of a white paper for the termite genome sequencing and
grant proposals to
USDA, NSF, and NIH. In the long term, they will help elucidate the interactions
between genes,
behavior, and environment that together result in a highly complex society
encompassing many
traits also observed in human societies.