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Sperm nuclear architecture is locally modified in presence of a Robertsonian translocation t(13;17).

Acloque H, Bonnet-Garnier A, Mompart F, Pinton A, Yerle-Bouissou M - PLoS ONE (2013)

Bottom Line: Altering this organization may interfere with the zygote development and reduce fertility or prolificity.Analysis of telomeres, centromeres and gonosomes repartition does not support a global nuclear disorganization.Altogether our results showed that chromosome fusion does not significantly alter sperm nucleus architecture but suggest that centromere remodelling after chromosome fusion locally impacts chromosome positioning.

View Article: PubMed Central - PubMed

Affiliation: INRA, UMR444 Génétique Cellulaire, Castanet Tolosan, France ; Université de Toulouse, INP, ENVT, UMR444 Génétique Cellulaire, Toulouse, France.

ABSTRACT
In mammals, the non-random organization of the sperm nucleus supports an early function during embryonic development. Altering this organization may interfere with the zygote development and reduce fertility or prolificity. Thus, rare studies on sperm cells from infertile patients described an altered nuclear organization that may be a cause or a consequence of their respective pathologies. Thereby, chromosomal rearrangements and aneuploidy can be studied not only for their adverse effects on production of normal/balanced gametes at meiosis but also for their possible impact on sperm nuclear architecture and the epigenetic consequences of altered chromosome positioning. We decided to compare the global architecture of sperm nuclei from boars, either with a normal chromosome composition or with a Robertsonian translocation involving chromosomes 13 and 17. We hypothesized that the fusion between these chromosomes may change their spatial organization and we examined to what extend it could also modify the global sperm nuclear architecture. Analysis of telomeres, centromeres and gonosomes repartition does not support a global nuclear disorganization. But specific analysis of chromosomes 13 and 17 territories highlights an influence of chromosome 17 for the positioning of the fused chromosomes within the nucleus. We also observed a specific clustering of centromeres depending of the chromosome subtypes. Altogether our results showed that chromosome fusion does not significantly alter sperm nucleus architecture but suggest that centromere remodelling after chromosome fusion locally impacts chromosome positioning.

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Related in: MedlinePlus

Telomere repartition in sperm nuclei.A. Morphology and dimensions of the porcine spermatozoa nucleus. B. Chromosome composition of the sperm cell from control animal with 18 autosomes and one sexual chromosome (X or Y), 38 telomeres in total and of the translocated sperm cell t(13;17) with 17 autosomes and one sexual chromosome (X or Y), 36 telomeres in total. C. DNA-FISH with telomere-specific LNA probes on porcine metaphase spreads. D–E. 3D-SpermFISH with a telomere-specific LNA probe and the resulting image segmentation obtained using NEMO. F. Boxplot representing the number of telomeres clusters in control and t(13;17) sperm nuclei. Mean values in each condition are represented above the boxplot with the p-value of the corresponding t-test. G. Observed distribution of telomere associations per nucleus in sperm nucleus of control (gold yellow) and t(13;17) (dark green) animals.
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pone-0078005-g001: Telomere repartition in sperm nuclei.A. Morphology and dimensions of the porcine spermatozoa nucleus. B. Chromosome composition of the sperm cell from control animal with 18 autosomes and one sexual chromosome (X or Y), 38 telomeres in total and of the translocated sperm cell t(13;17) with 17 autosomes and one sexual chromosome (X or Y), 36 telomeres in total. C. DNA-FISH with telomere-specific LNA probes on porcine metaphase spreads. D–E. 3D-SpermFISH with a telomere-specific LNA probe and the resulting image segmentation obtained using NEMO. F. Boxplot representing the number of telomeres clusters in control and t(13;17) sperm nuclei. Mean values in each condition are represented above the boxplot with the p-value of the corresponding t-test. G. Observed distribution of telomere associations per nucleus in sperm nucleus of control (gold yellow) and t(13;17) (dark green) animals.

Mentions: Pig sperm cells exhibit a particular morphology very similar to a paddle with a flat head (around 3 µm in depth) and a long antero-posterior axis (12 µm) and are quite different to sperm cells from human (with an ovoid shape) or mouse (with a typical hook morphology) (Fig. 1A). The nucleus contains 18 autosomes and one sexual chromosome leading to a total of 19 chromosomes and 38 telomeres (Fig. 1B).


Sperm nuclear architecture is locally modified in presence of a Robertsonian translocation t(13;17).

Acloque H, Bonnet-Garnier A, Mompart F, Pinton A, Yerle-Bouissou M - PLoS ONE (2013)

Telomere repartition in sperm nuclei.A. Morphology and dimensions of the porcine spermatozoa nucleus. B. Chromosome composition of the sperm cell from control animal with 18 autosomes and one sexual chromosome (X or Y), 38 telomeres in total and of the translocated sperm cell t(13;17) with 17 autosomes and one sexual chromosome (X or Y), 36 telomeres in total. C. DNA-FISH with telomere-specific LNA probes on porcine metaphase spreads. D–E. 3D-SpermFISH with a telomere-specific LNA probe and the resulting image segmentation obtained using NEMO. F. Boxplot representing the number of telomeres clusters in control and t(13;17) sperm nuclei. Mean values in each condition are represented above the boxplot with the p-value of the corresponding t-test. G. Observed distribution of telomere associations per nucleus in sperm nucleus of control (gold yellow) and t(13;17) (dark green) animals.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3815027&req=5

pone-0078005-g001: Telomere repartition in sperm nuclei.A. Morphology and dimensions of the porcine spermatozoa nucleus. B. Chromosome composition of the sperm cell from control animal with 18 autosomes and one sexual chromosome (X or Y), 38 telomeres in total and of the translocated sperm cell t(13;17) with 17 autosomes and one sexual chromosome (X or Y), 36 telomeres in total. C. DNA-FISH with telomere-specific LNA probes on porcine metaphase spreads. D–E. 3D-SpermFISH with a telomere-specific LNA probe and the resulting image segmentation obtained using NEMO. F. Boxplot representing the number of telomeres clusters in control and t(13;17) sperm nuclei. Mean values in each condition are represented above the boxplot with the p-value of the corresponding t-test. G. Observed distribution of telomere associations per nucleus in sperm nucleus of control (gold yellow) and t(13;17) (dark green) animals.
Mentions: Pig sperm cells exhibit a particular morphology very similar to a paddle with a flat head (around 3 µm in depth) and a long antero-posterior axis (12 µm) and are quite different to sperm cells from human (with an ovoid shape) or mouse (with a typical hook morphology) (Fig. 1A). The nucleus contains 18 autosomes and one sexual chromosome leading to a total of 19 chromosomes and 38 telomeres (Fig. 1B).

Bottom Line: Altering this organization may interfere with the zygote development and reduce fertility or prolificity.Analysis of telomeres, centromeres and gonosomes repartition does not support a global nuclear disorganization.Altogether our results showed that chromosome fusion does not significantly alter sperm nucleus architecture but suggest that centromere remodelling after chromosome fusion locally impacts chromosome positioning.

View Article: PubMed Central - PubMed

Affiliation: INRA, UMR444 Génétique Cellulaire, Castanet Tolosan, France ; Université de Toulouse, INP, ENVT, UMR444 Génétique Cellulaire, Toulouse, France.

ABSTRACT
In mammals, the non-random organization of the sperm nucleus supports an early function during embryonic development. Altering this organization may interfere with the zygote development and reduce fertility or prolificity. Thus, rare studies on sperm cells from infertile patients described an altered nuclear organization that may be a cause or a consequence of their respective pathologies. Thereby, chromosomal rearrangements and aneuploidy can be studied not only for their adverse effects on production of normal/balanced gametes at meiosis but also for their possible impact on sperm nuclear architecture and the epigenetic consequences of altered chromosome positioning. We decided to compare the global architecture of sperm nuclei from boars, either with a normal chromosome composition or with a Robertsonian translocation involving chromosomes 13 and 17. We hypothesized that the fusion between these chromosomes may change their spatial organization and we examined to what extend it could also modify the global sperm nuclear architecture. Analysis of telomeres, centromeres and gonosomes repartition does not support a global nuclear disorganization. But specific analysis of chromosomes 13 and 17 territories highlights an influence of chromosome 17 for the positioning of the fused chromosomes within the nucleus. We also observed a specific clustering of centromeres depending of the chromosome subtypes. Altogether our results showed that chromosome fusion does not significantly alter sperm nucleus architecture but suggest that centromere remodelling after chromosome fusion locally impacts chromosome positioning.

Show MeSH
Related in: MedlinePlus