Evolutionary re-wiring of regulatory genes in insects

Genes that control embryonic development have been well-studied in Drosophila and
other insect species. Since these genes are vital for embryonic patterning and survival,
loss or gain of function changes are likely to have deleterious effects, slowing the pace
of evolutionary variation. In fact, some of these genes, exemplified by the Hox gene
family, are so highly conserved that Hox genes from mammals can generate the same
phenotypes as their Drosophila counterparts when expressed ectopically in flies.
Despite this example of strong evolutionary conservation, we have found that other
embryonic regulatory genes have undergone extensive change in expression and
protein function during the radiation of insects. Other regulatory genes have been
gained or lost in different insect lineages. We have explored both the functional
conservation and the evolutionary variation in regulatory genes, focusing on genes
controlling segment formation. Our work has made use of selected insect species that
represent different branches of insect phylogeny. This work has involved the rearing
and development of genetic technology in non-model insects and our lab has benefited
from our “insect zoo” that enhances troubleshooting of protocols for different species.
Overall, we have found multiple examples of different types of genetic change
suggesting that, even for genes necessary for fundamental processes such as
embryonic development, evolutionary variation is extensive. Many outstanding
students, postdoctoral fellows, and staff have contributed to this work over the years,
which has been funded by the NSF and NIH (current grant NIGMS, R01GM113230).