Cannibalism in Blepharisma americanum : a genome comparison

Abstract

Cannibalism is a process in which an organism consumes a member of its own species. The process is intraspecies while predation is interspecies. Unlike predation, literature on the process of cannibalism is largely understudied, particularly in the microbial world. This study focuses on Blepharisma americanum , a species of eukaryotic microbe. In this species, cannibalism can be confirmed visually by a giant cannibal cell digesting victim cells within the food vacuoles. Cannibalism is regularly practiced in B. americanum and I attempt to elucidate the genetic differences between life states: cannibal and vegetative cells. I investigate using bioinformatic approaches: whole transcriptome amplification, high throughput sequencing, and phylogenomic transcript analysis. The data show heterogeneous transcript diversity between life states, indicating that while life state is determined visually, the genetic processes behind the state may be more complex. I also identified 15 candidate cannibalism gene families that are upregulated or downregulated in cannibal cells. Of the 15 gene families, I was able to link two of them to protein families involved in the autophagosome and membrane growth. I hope that future studies can continue to use the power of molecular study and bioinformatics to further the genetic study cannibalism in B. americanu