Intra-chromosomal gene conversion induced by a DNA double-strand break in Saccharomyces cerevisiae

J Mol Biol. 1988 May 20;201(2):247-60. doi: 10.1016/0022-2836(88)90136-2.

Abstract

We have stimulated mitotic and meiotic gene conversion between non-tandem direct repeats of ADE4 by a defined double-strand break imparted in vivo to one of two copies of the gene. The experimental design permitted us to distinguish unambiguously between reciprocal intra-chromosomal crossing over and non-reciprocal break-join events that could accompany the induced conversions. We observed that (1) less than 10% of the induced conversion events are accompanied by intra-chromosomal crossing over in both mitosis and meiosis; (2) non-reciprocal break-join is not stimulated by the double-strand breaks; (3) a double-strand break in meiosis is repaired off intra-chromosomal homology (if available) with approximately sevenfold preference over repair off the homologous chromosome. Our observations, analyzed in the light of previous investigations of spontaneous inter and intra-chromosomal crossing over and gene conversion, lead to the view that chromosomal configuration constrains intra-chromosomal crossing over accompanying conversion between closely spaced repeated genes during resolution of the conversion intermediate.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Chromosomes
  • Crossing Over, Genetic
  • DNA, Fungal*
  • Gene Conversion*
  • Meiosis
  • Mitosis
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / genetics*

Substances

  • DNA, Fungal