Thomas Hatzopoulos

Year: Sophomore

Major(s):  Bioinformatics, Computer Science

Mentor: Putonti, Catherine

Department: Biology

Project Title: Do Bacteria Have an Immune System?

Project Abstract: CRISPRs, clustered regularly interspaced short palindromic repeats, are sections of bacteria that grant immunity to certain types of bacteriophage (viral) infections. Species contain what are known as CRISPR arrays which contain short subsequences of viral genomic DNA. When a prokaryote is infected by the virus, the CRISPR system recognizes the foreign invader, through hybridization of the CRISPR sequence and the viral DNA, and launches a full-scale immune response. Previous research, looking at an archaebacteria species, found that just a few mutations (i.e., imperfect matches) between the CRISPR sequence and the viral DNA can lead to the virus¿ ability to evade the immune response. I am curious if this is true for CRISPRs within bacterial species as well and this will be the goal of my long-term research project. In the proposed work, however, I will tackle the first step in this process ¿ I will create an E. coli C strain with immunity to the bacteriophage (virus) Phi-X174 through the insertion of part of the viral sequence into the host’s CRISPR array. Different regions of the virus genome will be incorporated in order to see if there is any connection between the gene that the CRISPR sequence recognizes and the strength of the bacterial immune response. We will be able to see if the virus is able to evade the host response, looking at the genetic and phenotypic responses to infection.