scholarly journals Active and inactive transplacement of the M26 recombination hotspot in Schizosaccharomyces pombe.

Genetics ◽  
1995 ◽  
Vol 141 (1) ◽  
pp. 33-48
Author(s):  
J B Virgin ◽  
J Metzger ◽  
G R Smith
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Meiotic Recombination ◽  
Plasmid Dna ◽  
Context Effect ◽  
Intragenic Recombination ◽  
Multicopy Plasmid ◽  
Chromosomal Locus ◽  
Sequence Element ◽  
Recombination Hotspot ◽  
Recombination Hotspots

Abstract The ade6-M26 mutation of the fission yeast Schizosaccharomyces pombe creates a meiotic recombination hotspot that elevates ade6 intragenic recombination approximately 10-15-fold. A heptanucleotide sequence including the M26 point mutation is required but not sufficient for hotspot activity. We studied the effects of plasmid and chromosomal context on M26 hotspot activity. The M26 hotspot was inactive on a multicopy plasmid containing M26 embedded within 3.0 or 5.9 kb of ade6 DNA. Random S. pombe genomic fragments totaling approximately 7 Mb did not activate the M26 hotspot on a plasmid. M26 hotspot activity was maintained when 3.0-, 4.4-, and 5.9-kb ade6-M26 DNA fragments, with various amounts of non-S. pombe plasmid DNA, were integrated at the ura4 chromosomal locus, but only in certain configurations relative to the ura4 gene and the cointegrated plasmid DNA. Several integrations created new M26-independent recombination hotspots. In all cases the non-ade6 DNA was located > 1 kb from the M26 site, and in some cases > 2 kb. Because the chromosomal context effect was transmitted over large distances, and did not appear to be mediated by a single discrete DNA sequence element, we infer that the local chromatin structure has a pronounced effect on M26 hotspot activity.

scholarly journals Meiotic recombination-deficient mutants of Schizosaccharomyces pombe.

Genetics ◽  
1989 ◽  
Vol 123 (1) ◽  
pp. 45-54 ◽  
Author(s):  
A S Ponticelli ◽  
G R Smith
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Meiotic Recombination ◽  
Intragenic Recombination ◽  
Gene Products ◽  
Recombination Hotspot ◽  
Mutant Screen ◽  
Complementation Groups ◽  
Chromosome Iii ◽  
Rec Genes ◽  
Chromosome I

Abstract A mutant screen employing the ade6-M26 recombination hotspot was developed and used to isolate Schizosaccharomyces pombe mutants deficient in meiotic recombination. Nine rec mutations were recessive, defining six complementation groups, and reduced ade6 meiotic recombination 3-fold to greater than or equal to 300-fold when homozygous. Three recessive rec mutations analyzed further also reduced meiotic intragenic recombination at ura4 on chromosome III and intergenic recombination between pro2 and arg3 on chromosome I. The observed non-co-ordinate reductions of the recombinant frequencies in the three test intervals suggest a degree of locus (or intragenic vs. intergenic) specificity of the corresponding rec+ gene products. None of the mutations specifically inactivated the ade6-M26 hotspot. Additional rec genes may be identified with these methods.

scholarly journals Genetic and physical analysis of the M26 recombination hotspot of Schizosaccharomyces pombe.

Genetics ◽  
1988 ◽  
Vol 119 (3) ◽  
pp. 491-497
Author(s):  
A S Ponticelli ◽  
E P Sena ◽  
G R Smith
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Meiotic Recombination ◽  
Base Pair ◽  
Initiation Site ◽  
Mitotic Recombination ◽  
Physical Analysis ◽  
Nucleotide Change ◽  
Recombination Hotspot ◽  
Base Pair Mismatch

Abstract The ade6-M26 mutation of Schizosaccharomyces pombe has previously been reported to stimulate ade6 intragenic meiotic recombination. We report here that the ade6-M26 mutation is a single G----T nucleotide change, that M26 stimulated recombination within ade6 but not at other distinct loci, and that M26 stimulated meiotic but not mitotic recombination. In addition, M26 stimulated recombination within ade6 when M26 is homozygous; this result demonstrates that a base-pair mismatch at the M26 site was not required for the stimulation. These results are consistent with the ade6-M26 mutation creating a meiotic recombination initiation site.

scholarly journals Properties of Natural Double-Strand-Break Sites at a Recombination Hotspot in Saccharomyces cerevisiae

Genetics ◽  
2003 ◽  
Vol 165 (1) ◽  
pp. 101-114 ◽  
Author(s):  
Stuart J Haring ◽  
George R Halley ◽  
Alex J Jones ◽  
Robert E Malone
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Conversion ◽  
Meiotic Recombination ◽  
Strand Break ◽  
Double Strand Break ◽  
Recombination Hotspot ◽  
Recombination Hotspots ◽  
Naturally Occurring ◽  
High Level ◽  
Site Recognition

Abstract This study addresses three questions about the properties of recombination hotspots in Saccharomyces cerevisiae: How much DNA is required for double-strand-break (DSB) site recognition? Do naturally occurring DSB sites compete with each other in meiotic recombination? What role does the sequence located at the sites of DSBs play? In S. cerevisiae, the HIS2 meiotic recombination hotspot displays a high level of gene conversion, a 3′-to-5′ conversion gradient, and two DSB sites located ∼550 bp apart. Previous studies of hotspots, including HIS2, suggest that global chromosome structure plays a significant role in recombination activity, raising the question of how much DNA is sufficient for hotspot activity. We find that 11.5 kbp of the HIS2 region is sufficient to partially restore gene conversion and both DSBs when moved to another yeast chromosome. Using a variety of different constructs, studies of hotspots have indicated that DSB sites compete with one another for DSB formation. The two naturally occurring DSBs at HIS2 afforded us the opportunity to examine whether or not competition occurs between these native DSB sites. Small deletions of DNA at each DSB site affect only that site; analyses of these deletions show no competition occurring in cis or in trans, indicating that DSB formation at each site at HIS2 is independent. These small deletions significantly affect the frequency of DSB formation at the sites, indicating that the DNA sequence located at a DSB site can play an important role in recombination initiation.

Sequence requirement of the ade6-4095 meiotic recombination hotspot in Schizosaccharomyces pombe

Genetica ◽  
2017 ◽  
Vol 146 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Steven J. Foulis ◽  
Kyle R. Fowler ◽  
Walter W. Steiner
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Meiotic Recombination ◽  
Recombination Hotspot

scholarly journals Five RecA-like Proteins of Schizosaccharomyces pombe Are Involved in Meiotic Recombination

Genetics ◽  
2003 ◽  
Vol 165 (3) ◽  
pp. 1031-1043
Author(s):  
A L Grishchuk ◽  
J Kohli
Keyword(s):  
Escherichia Coli ◽  
Schizosaccharomyces Pombe ◽  
Meiotic Recombination ◽  
Sequence Similarity ◽  
Intragenic Recombination ◽  
Wild Type ◽  
Spore Viability ◽  
Viability Analysis ◽  
Recombination Protein ◽  
Recombination Gene

Abstract The genome of Schizosaccharomyces pombe contains five genes that code for proteins with sequence similarity to the Escherichia coli recombination protein RecA: rad51+, rhp55+, rhp57+, rlp1+, and dmc1+. We analyzed the effect of deletion of each of these genes on meiotic recombination and viability of spores. Meiotic recombination levels were different from wild type in all recA-related mutants in several genetic intervals, suggesting that all five RecA homologs of S. pombe are required for normal levels of meiotic recombination. Spore viability was reduced in rad51, rhp55, and rhp57 mutants, but not in rlp1 and dmc1. It is argued that reduction of crossover is not the only cause for the observed reduction of spore viability. Analysis of double and triple mutants revealed that Rad51 and Dmc1 play major and partially overlapping roles in meiotic recombination, while Rhp55, Rhp57, and Rlp1 play accessory roles. Remarkably, deletion of Rlp1 decreases the frequency of intergenic recombination (crossovers), but increases intragenic recombination (gene conversion). On the basis of our results, we present a model for the involvement of five RecA-like proteins of S. pombe in meiotic recombination and discuss their respective roles.

scholarly journals A Family of cAMP-Response-Element-Related DNA Sequences With Meiotic Recombination Hotspot Activity in Schizosaccharomyces pombe

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 59-68
Author(s):  
Mary E Fox ◽  
Takatomi Yamada ◽  
Kunihiro Ohta ◽  
Gerald R Smith
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Dna Sequences ◽  
Meiotic Recombination ◽  
Consensus Sequence ◽  
Micrococcal Nuclease ◽  
Open Chromatin ◽  
Camp Response Element ◽  
Response Element ◽  
Recombination Hotspot ◽  
Single Sequence

Abstract The heptamer sequence ATGACGT is essential for activity of the M26 meiotic recombination hotspot in the ade6 gene of Schizosaccharomyces pombe. Hotspot activity is associated with binding of the heterodimeric transcription factor Atf1·Pcr1 to M26. We have found that the sequences (C/T/G) TGACGT also bound Atf1·Pcr1 and acted as meiotic hotspots, but unlike M26 they must be followed by A or C for Atf1·Pcr1 binding and hotspot activity. The basis of the hotspot activity of CTGACGTA (ade6-3013) appears to be identical to that of M26: hotspot activity of both sequences was abolished in cells mutant for atf1, pcr1, spc1, or wis1 and was undetectable in mitotic recombination and in meiotic recombination when located on a plasmid. Both hotspot sequences were sites of micrococcal nuclease hypersensitivity in meiotic chromatin, suggesting that they create an open chromatin structure during meiosis at the site of the hotspots. The newly identified hotspot sequences (C/T/G)TGACGT(A/C) and M26 are closely related to the cAMP response element (CRE) consensus sequence for binding of cAMP-responsive transcription factors such as Atf1·Pcr1, suggesting a link between transcription and meiotic recombination. These results significantly expand the list of identified sequences with meiotic recombination hotspot activity in S. pombe from a single sequence to a family of CRE-related sequences.

scholarly journals Seventeen complementation groups of mutations decreasing meiotic recombination in Schizosaccharomyces pombe.

Genetics ◽  
1992 ◽  
Vol 130 (2) ◽  
pp. 251-262 ◽  
Author(s):  
L C De Veaux ◽  
N A Hoagland ◽  
G R Smith
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Meiotic Recombination ◽  
Class Ii ◽  
Class I ◽  
Intragenic Recombination ◽  
Class Iii ◽  
Multiple Alleles ◽  
Fold Reduction ◽  
Complementation Groups ◽  
Rec Genes

Abstract We have analyzed 43 recessive mutations reducing meiotic intragenic recombination in Schizosaccharomyces pombe. These mutations were isolated by a screen for reduced plasmid-by-chromosome recombination at the ade6 locus. Sixteen of the mutations define 10 new complementation groups, bringing to 17 the number of genes identified to be involved in meiotic recombination. The mutations were grouped into three discrete classes depending on the severity of the recombination deficiency in crosses involving the ade6-M26 recombination hotspot. Class I mutations caused at least a 1000-fold reduction in M26-stimulated intragenic recombination at the ade6 locus. Class II mutations reduced M26-stimulated recombination approximately 100-fold. Class III mutations caused a 3-10-fold reduction in either M26-stimulated or non-hotspot recombination. We obtained multiple alleles of class I and class II mutations, suggesting that we may be nearing saturation for mutations of this type. As a first step toward mapping, we used mitotic segregation to assign fourteen of the rec genes to chromosomes. Mutations in the six rec genes tested also caused a decrease in intragenic recombination at the ura4 locus; five of these mutations also reduced intergenic recombination between the pro2 and arg3 genes. These results indicate that these multiple rec gene products are required for high level meiotic recombination throughout the S. pombe genome.

scholarly journals Length asymmetry and heterozygosity strongly influences the evolution of poly-A microsatellites at meiotic recombination hotspots

2018 ◽  
Author(s):  
Angelika Heissl ◽  
Andrea J. Betancourt ◽  
Philipp Hermann ◽  
Gundula Povysil ◽  
Barbara Arbeithuber ◽  
...  
Keyword(s):  
Tandem Repeat ◽  
Meiotic Recombination ◽  
Short Tandem Repeat ◽  
Open Chromatin ◽  
Recombination Hotspot ◽  
Recombination Hotspots ◽  
Length Difference ◽  
Meiotic Recombination Hotspots ◽  
Short Tandem

AbstractMeiotic recombination has strong, but poorly understood, effects on short tandem repeat (STR) instability. Here, we screened thousands of single recombinant products to characterize the transmission and evolution of polymorphic poly-A repeats at a human recombination hotspot. We show that length asymmetry between heterozygous poly-As plays a key role in the recombination outcome and their transmission. A difference of 10 As (9A/19A) elevates the frequency of non-crossovers, complex recombination products, and long conversion tracts. Moreover, asymmetry also influences STR transmission: the shorter allele is transmitted more frequently (deletion bias) at the asymmetric STR (9A/19A), while the longer allele is favored (insertion bias) at the site with a small STR length difference (6A/7A). Finally, potentially due to this opposing insertion/deletion driven evolution, we find that poly-As are enriched at human recombination hotspots predominantly with short poly-As, possibly influencing open chromatin regions that in turn can activate hotspots.

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