Detection of Primary DNA Lesions by Transient Changes in Mating Behavior in Yeast Using the Alpha-Test.

Spontaneous or induced DNA lesions can result in stable gene mutations and chromosomal aberrations due to their inaccurate repair, ultimately resulting in phenotype changes. Some DNA lesions per se may interfere with transcription, leading to temporary phenocopies of mutations. The direct impact of primary DNA lesions on phenotype before their removal by repair is not well understood.

Host nucleases generate prespacers for primed adaptation in the type I-E CRISPR-Cas system.

CRISPR-Cas systems provide prokaryotes with adaptive immunity against foreign nucleic acids. In , immunity is acquired upon integration of 33-bp spacers into CRISPR arrays. DNA targets complementary to spacers get degraded and serve as a source of new spacers during a process called primed adaptation.

Detection of spacer precursors formed in vivo during primed CRISPR adaptation.

Type I CRISPR-Cas loci provide prokaryotes with a nucleic-acid-based adaptive immunity against foreign DNA. Immunity involves adaptation, the integration of ~30-bp DNA fragments, termed prespacers, into the CRISPR array as spacers, and interference, the targeted degradation of DNA containing a protospacer. Interference-driven DNA degradation can be coupled with primed adaptation, in which spacers are acquired from DNA surrounding the targeted protospacer.