title: Sequence non-specific double-strand breaks and interhomolog interactions prior to double-strand break formation at a meiotic recombination hot spot in yeast.
abstract: The HIS4LEU2 meiotic recombination hot spot specifies two double-strand break (DSB) sites, I and II. Results presented demonstrate that DSBs at site I occur at many positions throughout a region of approximately 150 bp; we infer that breaks occur in a sequence non-specific fashion. Single-strand nicks at sites I and II are not detectable. Analysis of the effects of a 36 bp linker insertion at site I reveals the existence of communication along and between homologs prior to DSB formation. In cis, the insertion allele causes an increase in DSBs at site I but a decrease in DSBs at site II. In trans, two effects are observed. One effect likely reflects very early pre-DSB interhomolog interactions; the second is suggestive of a later, more intimate interaction in which sites I and II on the two homologs all compete for DSBs. The existence of interhomolog interactions in early meiotic prophase can explain how the sites of crossovers come to lie between the homolog axes at pachytene.
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
authors.forename: L
authors.initials: L
authors.lastname: Xu
authors.forename: N
authors.initials: N
authors.lastname: Kleckner
mesh_terms: D050539:3-Isopropylmalate Dehydrogenase; D000429:Alcohol Oxidoreductases / Q000235:genetics; D000619:Aminohydrolases; D016477:Artifacts; D001426:Bacterial Proteins; D001483:Base Sequence; D004249:DNA Damage; D004271:DNA, Fungal / Q000235:genetics; D004277:DNA, Single-Stranded / Q000235:genetics; D015245:Deoxyribonuclease BamHI / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D004171:Diploidy; D005656:Fungal Proteins / Q000235:genetics; D008540:Meiosis; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D011755:Pyrophosphatases; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D012689:Sequence Homology, Nucleic Acid; D013573:Synaptonemal Complex; D014157:Transcription Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D004271:DNA, Fungal; D004277:DNA, Single-Stranded; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D000429:Alcohol Oxidoreductases; C092116:HIS4 protein, S cerevisiae; D050539:3-Isopropylmalate Dehydrogenase; D015245:Deoxyribonuclease BamHI; C035041:endodeoxyribonuclease MluI; D015252:Deoxyribonucleases, Type II Site-Specific; D000619:Aminohydrolases; D011755:Pyrophosphatases