Every living organism interacts with all sorts of microbes. The goal of our laboratory is to understand the mechanisms by which animal hosts and beneficial microbial symbionts communicate with an emphasis on how components of the innate immune system may influence these interactions. We use the Hawaiian bobtail squid, Euprymna scolopes as a model system to study the effects of beneficial bacteria on animal host tissues. The bobtai

The bobtail squid has two organs that each form symbioses with bacteria:

• In the light organ, the squid forms a binary relationship with the bioluminescent bacterium, Vibrio fischeri. This simple association has an advantage in that each partner can be raised independently in the laboratory and are readily available for molecular, biochemical, and genetic analyses.
• In the accessory nidamental gland (ANG), the squid houses a complex consortium of bacterial partners that assist in egg defense. This complexity more closely resembles the complexity of other symbioses in nature and helps us understand how hosts interact with a whole community of different bacteria.

By comparing and contrasting these two symbioses found in the same organism, we can identify broad, generalizable themes that govern host-microbe interactions in all sorts of systems.

Demonstrating how organ structure and microbial community organization contribute to symbiotic defense:

Kamp DL, Kerwin AH, McAnulty SJ, Nyholm SV. 2025, Organ structure and bacterial microbiogeography in a reproductive organ of the Hawaiian bobtail squid reveal dimensions of a defensive symbiosis. AEM

How microbial communities in symbiotic organs relate to evolutionary history:

Vijayan N, McAnulty SJ, Sanchez G, Jolly J, Ikeda Y, Nishiguchi MK, Réveillac E, Gestal C, Spady BL, Li DH, Burford BP, Kerwin AH, Nyholm SV. 2024. Evolutionary history influences the microbiomes of a female symbiotic reproductive organ in cephalopods. AEM

The formation of a symbiotic organ is dependent on the presence of symbiotic bacteria:

Mcanulty SJ, Kerwin AH, Koch E, Nuttall B, Schleicher TR, Rader BA, Nyholm SV, Collins AJ. (2023) “ Failure To Launch ” : Development of a Reproductive Organ Linked to Symbiotic Bacteria. mBio

Symbiotic bacteria from the accessory nidamental gland help protect squid eggs:

Kerwin, A. H., Gromek, S. M., Suria, A. M., Samples, R. M., Deoss, D. J., O’Donnell, K., Frasca Jr., S., Sutton, D. A. Wiederhold, N. P., Balunas, M. J., Nyholm, S. V. (2019) Shielding the Next Generation: Symbtiontic Bacteria from a Reproductive Organ Protective Bobtail Squid Eggs from Fungal Fouling. mBio

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