Current research

Evolutionary development of the insect olfactory system

A fundamental step for the evolution of the brain and behavior is the evolution of novel neural circuits. In the insect olfactory system, responses to odors are facilitated by populations or odorant sensory neurons (OSNs) in the olfactory system. All OSNs in a given population express a single receptor protein (responsible for determining neuronal response to odorants) and project together to the same target in the brain. The evolution of novel olfactory responses thus necessitates the evolution of new, functionally distinct OSN populations. I work to understand the molecular basis of OSN population identidy and function and how novel OSN populations are born using comparative and functional genetics approaches.



Olfactory sensory neurons in a clonal raider ant antenna.
Neurons innervating several olfactory sensilla are labelled in purple via electroporation. Cuticle autofluorescence (outer ring) also in purple, dapi-stained nuclei in cyan.

Olfactory neurogenomics and chemical communication in the clonal raider ant, Oocerea biroi

The eusocial insects are excellent models to understand the neurobiological and genetic basis of communication, and understanding their communication systems may shed light on the very foundations of social behavior. I am currently focusing on the genetics and neurobiology of chemical communication in the model eusocial insect Ooceraea biroi. So far I have annotated all chemosensory genes in the genome of O. biroi (Oxley et al. 2014) and used transcriptomics and phylogenetics to investigate the contributions of two protein families (OBPs and CSPs) towards chemical communication (McKenzie et al. 2014). My ongoing work uses comparative genomics, transcriptomics, and neuroanatomy to uncover genetic and neurobiological specializations for social communication in ants, especially in the odorant receptor (OR) gene family and the antennal lobe of the ant brain.






Clonal raider ant brain.
Neural connections (synapses) stained in purple (synorf antibody), neural fibers in green (actin stained with phalloiden), and DNA in blue (dapi)

.

Neuroanatomy of ants: evolution of the eusocial brain

Ants exhibit remarkably sophisticated social behavior, yet their brains can be smaller than that of a fruit fly ( < 100,000 neurons). Considering this, Darwin remarked "The brain of an ant is one of the most marvelous atoms of matter in the world, perhaps more so than the brain of a man" (The Descent of Man, 1871). Indeed the brain of the ant is very different from that of other insects and even other Hymenoptera (the group containing ants, wasps, and bees). To help us understand how this "marvelous atom" gives rise to the social behavior of ants, I am building a reference brain atlas for the model clonal raider ant using confocal microscopy and various flourescent staining techniques. I am also working to understand the development of the clonal raider ant brain, particularly the olfactory system, and in the future I plan to use comparative methods to investigate the evolutionary developmental neurobiology of ants.

Simple Research: What I study explained using only the ten hundred most used words

I look at brain pieces used by small animals that live together to talk to each other with smells. I think that animals that live together will have special brain pieces for talking to each other, and finding the brain pieces in these small animals and showing that they are different from other brain pieces will help show that. I also look at how brains change when animals start living together, especially as animals start talking to each other. Finally I look at the information inside animals which makes them the way they are and find the bits that make them able to talk to each other. I look at how these bits of information change to allow animals to live together and talk to each other.

Created using http://xkcd.com/simplewriter/