Chromosome pairing and meiotic recombination in Neurospora crassa spo11 mutants.
Some organisms, such as mammals, green plants and fungi, require double-strand breaks in DNA (DSBs) for synapsis of homologous chromosomes at pachynema. Drosophila melanogaster and Caenorhabditis elegans are exceptions, achieving synapsis independently of DSB. SPO11 is responsible for generating DSBs and perhaps for the initiation of recombination in all organisms. Although it was previously suggested that Neurospora may not require DSBs for synapsis, we report here that mutation of Neurospora spo11 disrupts meiosis, abolishing synapsis of homologous chromosomes during pachynema and resulting in ascospores that are frequently aneuploid and rarely viable. Alignment of homologues is partially restored after exposure of spo11 perithecia to ionising radiation. Crossing over in a spo11 mutant is reduced in two regions of the Neurospora genome as expected, but is unaffected in a third.
Bowring
Frederick J
FJ
School of Biological Sciences, Flinders University, Adelaide, SA, Australia.
Yeadon
P Jane
PJ
Stainer
Russell G
RG
Catcheside
David E A
DE
D000595:Amino Acid Sequence; D023902:Chromosome Pairing / Q000502:physiology* / Q000528:radiation effects; D015825:Chromosomes, Fungal / Q000737:chemistry*; D017931:DNA Primers; D004706:Endodeoxyribonucleases; D004950:Esterases / Q000235:genetics*; D020440:Gene Duplication; D008540:Meiosis / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D009492:Neurospora crassa / Q000235:genetics*; D017354:Point Mutation / Q000235:genetics; D011995:Recombination, Genetic / Q000235:genetics / Q000502:physiology*; D013045:Species Specificity; D013172:Spores, Fungal / Q000235:genetics; D000099257:Meiotic Recombination Protein SPO11
D017931:DNA Primers; D004706:Endodeoxyribonucleases; D004950:Esterases; D000099257:Meiotic Recombination Protein SPO11