Meeting Abstract
Tapeworms have a complex lifecycle that requires both definitive (carnivore) and intermediate (typically herbivore) hosts, with adult parasites developing in carnivore intestines following the consumption of herbivore tissues containing tapeworm cysts. Phylogenetic and evolutionary biology studies of tapeworms can provide valuable proxy insights into the history of definitive host carnivory and associated behavior. Three tapeworm species primarily parasitize humans: Taenia solium (secondary host: pigs), T. asiatica (pigs), and T. saginata (cattle). We are using an integrative functional and evolutionary genomics approach to test the hypothesis that these tapeworms may have evolved to withstand heat stresses associated with meat cooking, a uniquely human behavior. First, we heated T. solium cysts to temperatures from 37 to 56 ° C, followed by RNA sequencing to identify significantly differentially expressed genes. We also sequenced and assembled the genomes of 9 Taenia tapeworm species (including the three human taxa) to identify gene families with elevated duplication rates on the human lineages, and to intersect these results with those from the RNA-seq experiment. We identified genes differentially expressed under high temperature whose protein products are known to be involved in the heat stress response (e.g., heat shock 70 protein, q=4.2×10-16; universal stress protein, q=9.9×10-35; cytochrome c oxidase II, q=5.2×10-30). While our comparative genomic analyses are ongoing, we preliminarily observe significantly more heat shock protein gene copies in the genomes of the three human tapeworm species than in those of any other tapeworm.
