Meiotic Recombination in Neurospora crassa Proceeds by Two Pathways with Extensive Holliday Junction Migration
Analysis of thousands of Δmsh-2 octads using our fluorescent recombination system indicates that, as in other filamentous fungi, symmetric heteroduplex is common in the his-3 region of Neurospora crassa. Symmetric heteroduplex arises from Holliday junction migration, and we suggest this mechanism ex...
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Published in | PloS one Vol. 11; no. 1; p. e0147815 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
United States
Public Library of Science
26.01.2016
Public Library of Science (PLoS) |
Subjects | |
Online Access | Get full text |
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Summary: | Analysis of thousands of Δmsh-2 octads using our fluorescent recombination system indicates that, as in other filamentous fungi, symmetric heteroduplex is common in the his-3 region of Neurospora crassa. Symmetric heteroduplex arises from Holliday junction migration, and we suggest this mechanism explains the high frequency of His+ spores in heteroallelic crosses in which recombination is initiated cis to the his-3 allele further from the initiator, cog+. In contrast, when recombination is initiated cis to the his-3 allele closer to cog+, His+ spores are mainly a result of synthesis-dependent strand annealing, yielding asymmetric heteroduplex. Loss of Msh-2 function increases measures of allelic recombination in both his-3 and the fluorescent marker gene, indicating that mismatches in asymmetric heteroduplex, as in Saccharomyces cerevisiae, tend to be repaired in the direction of restoration. Furthermore, the presence of substantial numbers of conversion octads in crosses lacking Msh-2 function suggests that the disjunction pathway described in S. cerevisiae is also active in Neurospora, adding to evidence for a universal model for meiotic recombination. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Competing Interests: The authors have declared that no competing interests exist. Conceived and designed the experiments: PJY FJB. Performed the experiments: PJY FJB. Analyzed the data: PJY DEAC. Contributed reagents/materials/analysis tools: DEAC. Wrote the paper: PJY FJB DEAC. Provided the Neurospora stocks, equipment and facilities necessary for this project to proceed: DEAC. |
ISSN: | 1932-6203 1932-6203 |
DOI: | 10.1371/journal.pone.0147815 |