Abstracts (first author)
Phage response to prokaryotic CRISPR defense
Adaptive immune systems in prokaryotes are centered around repetitive loci called CRISPRs (clustered regularly interspaced short palindromic repeat), into which invader DNA fragments are incorporated (reviewed in ). CRISPR transcripts are processed into small RNAs that guide CRISPR-associated (Cas) proteins to invading nucleic acids by complementary base pairing [2,3]. Mobile genetic elements that have been incorporated into the CRISPR blacklist can escape host defense through point mutagenesis [4,5]. Escape mutagenesis induces a secondary immune response leading to rapid incorporation of new invader DNA fragments into the CRISPR locus . MGE’s can also escape CRISPR-immunity through alternative escape routes, including (partial) deletions of target sequences from their genome [4,5] and expressing CRISPR suppressors . These features lead to a complex and dynamic co-evolutionary arms race. During this presentation, first the insights gained into the molecular mechanism of this intriguing immune system will be briefly discussed [2,3,5,8], followed by a discussion of the role of CRISPR in bacteria-phage co-evolution ( and unpublished data).
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