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Recombination protein Tid1p controls resolution of cohesin-dependent linkages in meiosis in Saccharomyces cerevisiae.

Kateneva AV, Konovchenko AA, Guacci V, Dresser ME - J. Cell Biol. (2005)

Bottom Line: Genetic results indicate that the primary defect in these cells is a failure to resolve Mcd1p-mediated connections.Tid1p interacts with recombination enzymes Dmc1p and Rad51p and has an established role in recombination repair.We propose that Tid1p remodels Mcd1p-mediated cohesion early in meiotic prophase to facilitate interhomologue recombination and the subsequent segregation of homologous chromosomes.

View Article: PubMed Central - PubMed

Affiliation: Program in Molecular, Cell, and Developmental Biology, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104.

ABSTRACT
Sister chromatid cohesion and interhomologue recombination are coordinated to promote the segregation of homologous chromosomes instead of sister chromatids at the first meiotic division. During meiotic prophase in Saccharomyces cerevisiae, the meiosis-specific cohesin Rec8p localizes along chromosome axes and mediates most of the cohesion. The mitotic cohesin Mcd1p/Scc1p localizes to discrete spots along chromosome arms, and its function is not clear. In cells lacking Tid1p, which is a member of the SWI2/SNF2 family of helicase-like proteins that are involved in chromatin remodeling, Mcd1p and Rec8p persist abnormally through both meiotic divisions, and chromosome segregation fails in the majority of cells. Genetic results indicate that the primary defect in these cells is a failure to resolve Mcd1p-mediated connections. Tid1p interacts with recombination enzymes Dmc1p and Rad51p and has an established role in recombination repair. We propose that Tid1p remodels Mcd1p-mediated cohesion early in meiotic prophase to facilitate interhomologue recombination and the subsequent segregation of homologous chromosomes.

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Failure of rec8Δ to suppress the tid1Δ defect in sister chromatid separation in the spo11Δ spo13Δ background. (A) Percentage of binucleates. (B) Percentage of dumbbells. The reduction in rec8Δ tid1Δ, as compared with tid1Δ, results from cells being blocked earlier (see C). (A and B) spo11Δ spo13Δ, dashed line with squares; spo11Δ spo13Δ tid1Δ, dashed line with triangles; spo11Δ spo13Δ rec8Δ, solid line with squares; spo11Δ spo13Δ rec8Δ tid1Δ, solid line with triangles. Progression of cells through the division is monitored using DAPI-stained chromatin. At least 200 cells were counted at each time point. (C) Spindle appearance in cells with a single unstretched mass of chromatin (as determined by DAPI staining; not depicted) in spread preparations of nuclei after 12 h of sporulation. SPB and short spindles labeled with antitubulin antibody are shown. Percentages shown are for cells of that appearance in the total population. At least 300 cells were scored for each genotype. Bars, 2 μm.
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fig4: Failure of rec8Δ to suppress the tid1Δ defect in sister chromatid separation in the spo11Δ spo13Δ background. (A) Percentage of binucleates. (B) Percentage of dumbbells. The reduction in rec8Δ tid1Δ, as compared with tid1Δ, results from cells being blocked earlier (see C). (A and B) spo11Δ spo13Δ, dashed line with squares; spo11Δ spo13Δ tid1Δ, dashed line with triangles; spo11Δ spo13Δ rec8Δ, solid line with squares; spo11Δ spo13Δ rec8Δ tid1Δ, solid line with triangles. Progression of cells through the division is monitored using DAPI-stained chromatin. At least 200 cells were counted at each time point. (C) Spindle appearance in cells with a single unstretched mass of chromatin (as determined by DAPI staining; not depicted) in spread preparations of nuclei after 12 h of sporulation. SPB and short spindles labeled with antitubulin antibody are shown. Percentages shown are for cells of that appearance in the total population. At least 300 cells were scored for each genotype. Bars, 2 μm.

Mentions: The timely turnover of Pds1p in spo11Δ spo13Δ tid1Δ indicates that cells are not blocked in metaphase but, rather, progress into a defective anaphase in which sister chromatids fail to segregate. In meiosis, the maintenance of sister chromatid cohesion requires the meiosis-specific cohesin Rec8p, and its cleavage is required for chromosome segregation in anaphase (Klein et al., 1999; Buonomo et al., 2000). One possible reason for the failure of sister segregation in tid1Δ cells is the persistence of Rec8p-based cohesin complexes on chromosomes. To test this possibility, REC8 was deleted in the spo11Δ spo13Δ background, where the effect of tid1Δ on sister chromatid separation is most obvious. The deletion of REC8 does not rescue the defect of sister chromatid separation in spo11Δ spo13Δ tid1Δ. The percentage of cells that progress past anaphase (binucleates) is similar in spo11Δ spo13Δ tid1Δ and in spo11Δ spo13Δ rec8Δ tid1Δ (Fig. 4 A). The percentage of dumbbells is reduced in spo11Δ spo13Δ rec8Δ tid1Δ (Fig. 4 B) because more cells are blocked earlier with a single unstretched mass of chromatin (not depicted). To determine the fraction of cells that were blocked with short spindles, spread preparations of nuclei were prepared after 12 h of sporulation, and the spindle was visualized by immunostaining (Fig. 4 C). A large fraction of spo11Δ spo13Δ rec8Δ tid1Δ cells is arrested with short spindles (43% in spo11Δ spo13Δ rec8Δ tid1Δ vs. 2% in spo11Δ spo13Δ rec8Δ at 12 h of sporulation). Thus, the deletion of REC8 fails to suppress the tid1Δ-mediated block to sister segregation.


Recombination protein Tid1p controls resolution of cohesin-dependent linkages in meiosis in Saccharomyces cerevisiae.

Kateneva AV, Konovchenko AA, Guacci V, Dresser ME - J. Cell Biol. (2005)

Failure of rec8Δ to suppress the tid1Δ defect in sister chromatid separation in the spo11Δ spo13Δ background. (A) Percentage of binucleates. (B) Percentage of dumbbells. The reduction in rec8Δ tid1Δ, as compared with tid1Δ, results from cells being blocked earlier (see C). (A and B) spo11Δ spo13Δ, dashed line with squares; spo11Δ spo13Δ tid1Δ, dashed line with triangles; spo11Δ spo13Δ rec8Δ, solid line with squares; spo11Δ spo13Δ rec8Δ tid1Δ, solid line with triangles. Progression of cells through the division is monitored using DAPI-stained chromatin. At least 200 cells were counted at each time point. (C) Spindle appearance in cells with a single unstretched mass of chromatin (as determined by DAPI staining; not depicted) in spread preparations of nuclei after 12 h of sporulation. SPB and short spindles labeled with antitubulin antibody are shown. Percentages shown are for cells of that appearance in the total population. At least 300 cells were scored for each genotype. Bars, 2 μm.
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Related In: Results  -  Collection

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fig4: Failure of rec8Δ to suppress the tid1Δ defect in sister chromatid separation in the spo11Δ spo13Δ background. (A) Percentage of binucleates. (B) Percentage of dumbbells. The reduction in rec8Δ tid1Δ, as compared with tid1Δ, results from cells being blocked earlier (see C). (A and B) spo11Δ spo13Δ, dashed line with squares; spo11Δ spo13Δ tid1Δ, dashed line with triangles; spo11Δ spo13Δ rec8Δ, solid line with squares; spo11Δ spo13Δ rec8Δ tid1Δ, solid line with triangles. Progression of cells through the division is monitored using DAPI-stained chromatin. At least 200 cells were counted at each time point. (C) Spindle appearance in cells with a single unstretched mass of chromatin (as determined by DAPI staining; not depicted) in spread preparations of nuclei after 12 h of sporulation. SPB and short spindles labeled with antitubulin antibody are shown. Percentages shown are for cells of that appearance in the total population. At least 300 cells were scored for each genotype. Bars, 2 μm.
Mentions: The timely turnover of Pds1p in spo11Δ spo13Δ tid1Δ indicates that cells are not blocked in metaphase but, rather, progress into a defective anaphase in which sister chromatids fail to segregate. In meiosis, the maintenance of sister chromatid cohesion requires the meiosis-specific cohesin Rec8p, and its cleavage is required for chromosome segregation in anaphase (Klein et al., 1999; Buonomo et al., 2000). One possible reason for the failure of sister segregation in tid1Δ cells is the persistence of Rec8p-based cohesin complexes on chromosomes. To test this possibility, REC8 was deleted in the spo11Δ spo13Δ background, where the effect of tid1Δ on sister chromatid separation is most obvious. The deletion of REC8 does not rescue the defect of sister chromatid separation in spo11Δ spo13Δ tid1Δ. The percentage of cells that progress past anaphase (binucleates) is similar in spo11Δ spo13Δ tid1Δ and in spo11Δ spo13Δ rec8Δ tid1Δ (Fig. 4 A). The percentage of dumbbells is reduced in spo11Δ spo13Δ rec8Δ tid1Δ (Fig. 4 B) because more cells are blocked earlier with a single unstretched mass of chromatin (not depicted). To determine the fraction of cells that were blocked with short spindles, spread preparations of nuclei were prepared after 12 h of sporulation, and the spindle was visualized by immunostaining (Fig. 4 C). A large fraction of spo11Δ spo13Δ rec8Δ tid1Δ cells is arrested with short spindles (43% in spo11Δ spo13Δ rec8Δ tid1Δ vs. 2% in spo11Δ spo13Δ rec8Δ at 12 h of sporulation). Thus, the deletion of REC8 fails to suppress the tid1Δ-mediated block to sister segregation.

Bottom Line: Genetic results indicate that the primary defect in these cells is a failure to resolve Mcd1p-mediated connections.Tid1p interacts with recombination enzymes Dmc1p and Rad51p and has an established role in recombination repair.We propose that Tid1p remodels Mcd1p-mediated cohesion early in meiotic prophase to facilitate interhomologue recombination and the subsequent segregation of homologous chromosomes.

View Article: PubMed Central - PubMed

Affiliation: Program in Molecular, Cell, and Developmental Biology, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104.

ABSTRACT
Sister chromatid cohesion and interhomologue recombination are coordinated to promote the segregation of homologous chromosomes instead of sister chromatids at the first meiotic division. During meiotic prophase in Saccharomyces cerevisiae, the meiosis-specific cohesin Rec8p localizes along chromosome axes and mediates most of the cohesion. The mitotic cohesin Mcd1p/Scc1p localizes to discrete spots along chromosome arms, and its function is not clear. In cells lacking Tid1p, which is a member of the SWI2/SNF2 family of helicase-like proteins that are involved in chromatin remodeling, Mcd1p and Rec8p persist abnormally through both meiotic divisions, and chromosome segregation fails in the majority of cells. Genetic results indicate that the primary defect in these cells is a failure to resolve Mcd1p-mediated connections. Tid1p interacts with recombination enzymes Dmc1p and Rad51p and has an established role in recombination repair. We propose that Tid1p remodels Mcd1p-mediated cohesion early in meiotic prophase to facilitate interhomologue recombination and the subsequent segregation of homologous chromosomes.

Show MeSH
Related in: MedlinePlus