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Separable Crossover-Promoting and Crossover-Constraining Aspects of Zip1 Activity during Budding Yeast Meiosis.

Voelkel-Meiman K, Johnston C, Thappeta Y, Subramanian VV, Hochwagen A, MacQueen AJ - PLoS Genet. (2015)

Bottom Line: While stable, full-length SC does not assemble in S. cerevisiae cells expressing K. lactis ZIP1, aggregates of K. lactis Zip1 displayed by S. cerevisiae meiotic nuclei are decorated with SC-associated proteins, and K. lactis Zip1 promotes the SUMOylation of the SC central element protein Ecm11, suggesting that K. lactis Zip1 functionally interfaces with components of the S. cerevisiae synapsis machinery.This separation-of-function version of Zip1 thus reveals that neither assembled SC nor MutSγ is required for Mlh3-dependent crossover formation per se in budding yeast.Our data suggest that features of S. cerevisiae Zip1 or of the assembled SC in S. cerevisiae normally constrain MutLγ to preferentially promote resolution of MutSγ-associated recombination intermediates.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, Connecticut, United States of America.

ABSTRACT
Accurate chromosome segregation during meiosis relies on the presence of crossover events distributed among all chromosomes. MutSγ and MutLγ homologs (Msh4/5 and Mlh1/3) facilitate the formation of a prominent group of meiotic crossovers that mature within the context of an elaborate chromosomal structure called the synaptonemal complex (SC). SC proteins are required for intermediate steps in the formation of MutSγ-MutLγ crossovers, but whether the assembled SC structure per se is required for MutSγ-MutLγ-dependent crossover recombination events is unknown. Here we describe an interspecies complementation experiment that reveals that the mature SC is dispensable for the formation of Mlh3-dependent crossovers in budding yeast. Zip1 forms a major structural component of the budding yeast SC, and is also required for MutSγ and MutLγ-dependent crossover formation. Kluyveromyces lactis ZIP1 expressed in place of Saccharomyces cerevisiae ZIP1 in S. cerevisiae cells fails to support SC assembly (synapsis) but promotes wild-type crossover levels in those nuclei that progress to form spores. While stable, full-length SC does not assemble in S. cerevisiae cells expressing K. lactis ZIP1, aggregates of K. lactis Zip1 displayed by S. cerevisiae meiotic nuclei are decorated with SC-associated proteins, and K. lactis Zip1 promotes the SUMOylation of the SC central element protein Ecm11, suggesting that K. lactis Zip1 functionally interfaces with components of the S. cerevisiae synapsis machinery. Moreover, K. lactis Zip1-mediated crossovers rely on S. cerevisiae synapsis initiation proteins Zip3, Zip4, Spo16, as well as the Mlh3 protein, as do the crossovers mediated by S. cerevisiae Zip1. Surprisingly, however, K. lactis Zip1-mediated crossovers are largely Msh4/Msh5 (MutSγ)-independent. This separation-of-function version of Zip1 thus reveals that neither assembled SC nor MutSγ is required for Mlh3-dependent crossover formation per se in budding yeast. Our data suggest that features of S. cerevisiae Zip1 or of the assembled SC in S. cerevisiae normally constrain MutLγ to preferentially promote resolution of MutSγ-associated recombination intermediates.

No MeSH data available.


Related in: MedlinePlus

Four-spore viable tetrads from K. l. ZIP1 meioses exhibit wild-type crossover levels, largely independent of Msh4, with diminished interference.Cartoon in (A) displays the markers used to define six genetic intervals in which crossing over was assessed in spores from S. c. ZIP1 and K. l. ZIP1-expressing S. cerevisiae strains (YT131, YT125, AM3313 and YT152). Graph in (B) plots the map distances (+/- S. E.) for each of the six intervals (labeled on the x axis) that were calculated from linkage analysis in 4-spore viable tetrads from each of the four strains analyzed (S. c. ZIP1 +/- MSH4 are indicated in darker and lighter blue, respectively while K. l. ZIP1 +/- MSH4 are indicated in darker and lighter green.). The specific values for map distance are listed in Table 2. Cartoon in (C) depicts observable (solid dark arrow) or undetectable (gray, dotted arrow) interference acting between adjacent genetic intervals on chromosome III, as measured by the “interference ratio” method (see Text for details) [74,75]. Strain genotypes are indicated at left. The interference ratio gives an estimate of the strength of interference; P values from chi-square analysis of the distribution of tetrad types derived from recombinant versus non-recombinant groups (Instat, Graphpad.com; S5 Table), as well as statistical analysis of the significance of differences between map lengths calculated by tetrad types (Stahl Online Tools; S5 Table) were used to determine whether adjacent intervals exhibited interference. Graph in (D) shows the genetic interference values obtained for each genetic interval (labeled on the x axis) when the number of four-chromatid double crossovers observed (NPDs) are compared to the number expected if there was no interference [76]. The red line marks an interference value of 1, which is equal to an absence of positive interference. The specific values for both map distance and interference measured in this manner are listed in Table 2.
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pgen.1005335.g006: Four-spore viable tetrads from K. l. ZIP1 meioses exhibit wild-type crossover levels, largely independent of Msh4, with diminished interference.Cartoon in (A) displays the markers used to define six genetic intervals in which crossing over was assessed in spores from S. c. ZIP1 and K. l. ZIP1-expressing S. cerevisiae strains (YT131, YT125, AM3313 and YT152). Graph in (B) plots the map distances (+/- S. E.) for each of the six intervals (labeled on the x axis) that were calculated from linkage analysis in 4-spore viable tetrads from each of the four strains analyzed (S. c. ZIP1 +/- MSH4 are indicated in darker and lighter blue, respectively while K. l. ZIP1 +/- MSH4 are indicated in darker and lighter green.). The specific values for map distance are listed in Table 2. Cartoon in (C) depicts observable (solid dark arrow) or undetectable (gray, dotted arrow) interference acting between adjacent genetic intervals on chromosome III, as measured by the “interference ratio” method (see Text for details) [74,75]. Strain genotypes are indicated at left. The interference ratio gives an estimate of the strength of interference; P values from chi-square analysis of the distribution of tetrad types derived from recombinant versus non-recombinant groups (Instat, Graphpad.com; S5 Table), as well as statistical analysis of the significance of differences between map lengths calculated by tetrad types (Stahl Online Tools; S5 Table) were used to determine whether adjacent intervals exhibited interference. Graph in (D) shows the genetic interference values obtained for each genetic interval (labeled on the x axis) when the number of four-chromatid double crossovers observed (NPDs) are compared to the number expected if there was no interference [76]. The red line marks an interference value of 1, which is equal to an absence of positive interference. The specific values for both map distance and interference measured in this manner are listed in Table 2.

Mentions: Since crossover recombination events are critical for the formation of the stable connections between homologs that ensure proper chromosome disjunction at meiosis I, it is reasonable to speculate that the basis for the diminished viability of spore products from K. l. Zip1-expressing S. cerevisiae strains lies in a failure of K. l. Zip1 to rescue S. c. Zip1’s crossover function. We therefore assessed crossover formation in four consecutive intervals on chromosome III, one interval on chromosome VIII and one interval on chromosome XI in S. cerevisiae cells expressing K. l. ZIP1 (Fig 6B and Table 2).


Separable Crossover-Promoting and Crossover-Constraining Aspects of Zip1 Activity during Budding Yeast Meiosis.

Voelkel-Meiman K, Johnston C, Thappeta Y, Subramanian VV, Hochwagen A, MacQueen AJ - PLoS Genet. (2015)

Four-spore viable tetrads from K. l. ZIP1 meioses exhibit wild-type crossover levels, largely independent of Msh4, with diminished interference.Cartoon in (A) displays the markers used to define six genetic intervals in which crossing over was assessed in spores from S. c. ZIP1 and K. l. ZIP1-expressing S. cerevisiae strains (YT131, YT125, AM3313 and YT152). Graph in (B) plots the map distances (+/- S. E.) for each of the six intervals (labeled on the x axis) that were calculated from linkage analysis in 4-spore viable tetrads from each of the four strains analyzed (S. c. ZIP1 +/- MSH4 are indicated in darker and lighter blue, respectively while K. l. ZIP1 +/- MSH4 are indicated in darker and lighter green.). The specific values for map distance are listed in Table 2. Cartoon in (C) depicts observable (solid dark arrow) or undetectable (gray, dotted arrow) interference acting between adjacent genetic intervals on chromosome III, as measured by the “interference ratio” method (see Text for details) [74,75]. Strain genotypes are indicated at left. The interference ratio gives an estimate of the strength of interference; P values from chi-square analysis of the distribution of tetrad types derived from recombinant versus non-recombinant groups (Instat, Graphpad.com; S5 Table), as well as statistical analysis of the significance of differences between map lengths calculated by tetrad types (Stahl Online Tools; S5 Table) were used to determine whether adjacent intervals exhibited interference. Graph in (D) shows the genetic interference values obtained for each genetic interval (labeled on the x axis) when the number of four-chromatid double crossovers observed (NPDs) are compared to the number expected if there was no interference [76]. The red line marks an interference value of 1, which is equal to an absence of positive interference. The specific values for both map distance and interference measured in this manner are listed in Table 2.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4482702&req=5

pgen.1005335.g006: Four-spore viable tetrads from K. l. ZIP1 meioses exhibit wild-type crossover levels, largely independent of Msh4, with diminished interference.Cartoon in (A) displays the markers used to define six genetic intervals in which crossing over was assessed in spores from S. c. ZIP1 and K. l. ZIP1-expressing S. cerevisiae strains (YT131, YT125, AM3313 and YT152). Graph in (B) plots the map distances (+/- S. E.) for each of the six intervals (labeled on the x axis) that were calculated from linkage analysis in 4-spore viable tetrads from each of the four strains analyzed (S. c. ZIP1 +/- MSH4 are indicated in darker and lighter blue, respectively while K. l. ZIP1 +/- MSH4 are indicated in darker and lighter green.). The specific values for map distance are listed in Table 2. Cartoon in (C) depicts observable (solid dark arrow) or undetectable (gray, dotted arrow) interference acting between adjacent genetic intervals on chromosome III, as measured by the “interference ratio” method (see Text for details) [74,75]. Strain genotypes are indicated at left. The interference ratio gives an estimate of the strength of interference; P values from chi-square analysis of the distribution of tetrad types derived from recombinant versus non-recombinant groups (Instat, Graphpad.com; S5 Table), as well as statistical analysis of the significance of differences between map lengths calculated by tetrad types (Stahl Online Tools; S5 Table) were used to determine whether adjacent intervals exhibited interference. Graph in (D) shows the genetic interference values obtained for each genetic interval (labeled on the x axis) when the number of four-chromatid double crossovers observed (NPDs) are compared to the number expected if there was no interference [76]. The red line marks an interference value of 1, which is equal to an absence of positive interference. The specific values for both map distance and interference measured in this manner are listed in Table 2.
Mentions: Since crossover recombination events are critical for the formation of the stable connections between homologs that ensure proper chromosome disjunction at meiosis I, it is reasonable to speculate that the basis for the diminished viability of spore products from K. l. Zip1-expressing S. cerevisiae strains lies in a failure of K. l. Zip1 to rescue S. c. Zip1’s crossover function. We therefore assessed crossover formation in four consecutive intervals on chromosome III, one interval on chromosome VIII and one interval on chromosome XI in S. cerevisiae cells expressing K. l. ZIP1 (Fig 6B and Table 2).

Bottom Line: While stable, full-length SC does not assemble in S. cerevisiae cells expressing K. lactis ZIP1, aggregates of K. lactis Zip1 displayed by S. cerevisiae meiotic nuclei are decorated with SC-associated proteins, and K. lactis Zip1 promotes the SUMOylation of the SC central element protein Ecm11, suggesting that K. lactis Zip1 functionally interfaces with components of the S. cerevisiae synapsis machinery.This separation-of-function version of Zip1 thus reveals that neither assembled SC nor MutSγ is required for Mlh3-dependent crossover formation per se in budding yeast.Our data suggest that features of S. cerevisiae Zip1 or of the assembled SC in S. cerevisiae normally constrain MutLγ to preferentially promote resolution of MutSγ-associated recombination intermediates.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, Connecticut, United States of America.

ABSTRACT
Accurate chromosome segregation during meiosis relies on the presence of crossover events distributed among all chromosomes. MutSγ and MutLγ homologs (Msh4/5 and Mlh1/3) facilitate the formation of a prominent group of meiotic crossovers that mature within the context of an elaborate chromosomal structure called the synaptonemal complex (SC). SC proteins are required for intermediate steps in the formation of MutSγ-MutLγ crossovers, but whether the assembled SC structure per se is required for MutSγ-MutLγ-dependent crossover recombination events is unknown. Here we describe an interspecies complementation experiment that reveals that the mature SC is dispensable for the formation of Mlh3-dependent crossovers in budding yeast. Zip1 forms a major structural component of the budding yeast SC, and is also required for MutSγ and MutLγ-dependent crossover formation. Kluyveromyces lactis ZIP1 expressed in place of Saccharomyces cerevisiae ZIP1 in S. cerevisiae cells fails to support SC assembly (synapsis) but promotes wild-type crossover levels in those nuclei that progress to form spores. While stable, full-length SC does not assemble in S. cerevisiae cells expressing K. lactis ZIP1, aggregates of K. lactis Zip1 displayed by S. cerevisiae meiotic nuclei are decorated with SC-associated proteins, and K. lactis Zip1 promotes the SUMOylation of the SC central element protein Ecm11, suggesting that K. lactis Zip1 functionally interfaces with components of the S. cerevisiae synapsis machinery. Moreover, K. lactis Zip1-mediated crossovers rely on S. cerevisiae synapsis initiation proteins Zip3, Zip4, Spo16, as well as the Mlh3 protein, as do the crossovers mediated by S. cerevisiae Zip1. Surprisingly, however, K. lactis Zip1-mediated crossovers are largely Msh4/Msh5 (MutSγ)-independent. This separation-of-function version of Zip1 thus reveals that neither assembled SC nor MutSγ is required for Mlh3-dependent crossover formation per se in budding yeast. Our data suggest that features of S. cerevisiae Zip1 or of the assembled SC in S. cerevisiae normally constrain MutLγ to preferentially promote resolution of MutSγ-associated recombination intermediates.

No MeSH data available.


Related in: MedlinePlus