Alison L. Gould

PhD, Ecology and Evolutionary Biology

Specificity of Microbial Symbioses

Photobacterium mandapamensis – the luminous symbiont of the sea urchin cardinalfish, Siphamia tubifer

In order for a specific host-microbe association to evolve, the symbiotic partnership must be stably re-established by each new generation of hosts. I am investigating the mechanisms involved in maintaining the specificity of microbial symbioses from the broad evolutionary scale down to the molecular level. To do so, I study a highly specific, binary symbiosis between a coral reef fish (Siphamia tubifer) and a luminous bacterium (Photobacterium mandapamensis).

My previous research showed that unique aspects of the host’s life history and behavioral ecology, play important roles in promoting specificity of the bioluminescent association between host generations. To test this, I applied genomic methods to look for patterns of population structure in the host fish and its luminous symbiont. Using museum genomics I also determined that the high degree of specificity of the bioluminescent symbiosis is conserved across the host genus and through time and space. Ongoing projects and future work will focus on defining the molecular mechanisms that regulate symbiont recognition and the establishment of this highly specific association.