Meeting Abstract
Many marine host-pathogen systems are poorly understood, and even less is known about how global climate change will affect the mechanisms of these systems. In the abalone and Rickettsiales-like organism (RLO) system, the RLO infects abalone digestive tissues and leads to extreme starvation and a characteristic “withering” of the gastropod foot. First identified in black abalone in California after an El Niño event, the withering syndrome-causing RLO (WS-RLO) has been seen in various sites around the world, and has been found in at least low levels in all abalone species examined, yet not all express WS1. Some abalone species appear to be highly resistant to the disease, unless held at extremely high temperatures. This suggests that the resistant species possess some physiological resistance to the effects of high temperature. Our goal is to develop a detailed understanding of the abalone digestive system and the mechanisms for differential resistance across the Haliotis (abalone) genus. In order to clarify differential susceptibility in geographically neighboring species (such as the highly susceptible red abalone H. rufescens and relatively resistant green abalone H. fulgens), we are creating a robust phylogeny of Haliotis to determine whether certain branches are more susceptible to WS. This phylogenetic tree was created using concatenated data from two multiple mitochondrial (16s and cytb) and three nuclear genes (h3 and its1/2), and will result in the most robust phylogeny of eastern Pacific Haliotids to date. Interestingly, the two most resistant species, H. fulgens and H. corrugata, are sister taxa that form a clade separate from the other California taxa. Ref:1Crosson, L.M. et al. (2014) Abalone withering syndrome: distribution, impacts, current diagnostic methods and new findings. Diseases of Aquatic Organisms 108, 261-270.
