Figure 1.
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.
Figure 2.
Distribution of chromocenters in sperm nuclei.
A. Representation of centromeres labeled either by AC6 or SSCRS2A probes. AC6 (red dots) specifically labeled the centromere of the six porcine acrocentric chromosomes (SSC13,14,15,16,17 and 18) and SSCSR2A (green dots) specifically labeled the centromeres of the porcine chromosomes SSC2 to SSC11 and SSCX or SSCY (11 centromeres). Centromeres from SSC1 and SSC12 are not labeled by these probes. Specific labeling was checked on porcine metaphase spreads and 3D-SpermFISH was performed on sperm nucleus. B. Distribution of chromocenters in control sperm nuclei using AC6 and SSCRS2A probes. C. Percentage of nuclei containing associations of chromocenters for both AC6 and SSCR2A labeling. Arrowheads highlight associations in three different cases exemplified here: no association, 1 association or 2 associations D–E. Violin plots representing chromocenters distribution in sperm nuclei from control (gold yellow) and t(13;17) animals. Significant differences were observed for AC6 labeling (E) with less AC6 positive chromocenters in t(13;17) animal. F. Violin plots representing the number of nuclei with AC6 and SSCRS2A associations in sperm nuclei from control and t(13;17) animals.
Figure 3.
SSCX and SSCY are non random localized in the sperm nucleus.
A. Chromosome paints for SSCX (red) and SSCY (green) were checked on metaphase spreads and 3D-SpermFISH was performed on sperm nuclei. B. Spatial representation of the different axis studied. Regarding the antero-posterior axis, 0% represents the most posterior part of the axis while 100% the more anterior part. For the medio-lateral axis, 0% represents the center and 100% the border of the nucleus. This axis is not lateralized and represents similarly left and right localization. C. SSCX and SSCY distributions along the anterior axis in control sperm nuclei. Note that SSCY is significantly more apical than SSCX and that the localization of sexual chromosomes is not random. SSCX and SSCY distributions are also visualized on violin plots inserted within the sperm nucleus head to visualize their respective position along the antero-posterior axis. Mean values for each chromosome are represented above the violinplot with the p-value of the corresponding t-test. D. SSCX and SSCY distributions along the medio-lateral axis in control sperm nuclei. Note that SSCX is uniformly distributed along the axis while SSCY is preferentially in the center region. SSCX and SSCY distributions are also visualized on violin plots inserted within the sperm nucleus head to visualize their respective position along the medio-lateral axis. Mean values for each chromosome are represented above the violinplot with the p-value of the corresponding t-test.
Figure 4.
Robertsonian translocation t(13;17) does not affect SSCX and SSCY localization in the sperm nucleus.
A–B. Comparison of SSCX distribution along the antero-posterior (A) and medio-lateral (B) axis in sperm nuclei from control (gold yellow) and t(13;17)(dark green) animals. Mean values for each condition are represented above the violinplot with the p-value of the corresponding t-test. C–D. Comparison of SSCY distribution along the antero-posterior (A) and medio-lateral (B) axis in sperm nuclei from control (gold yellow) and t(13;17)(dark green) animals. Mean values for each condition are represented above the violinplot with the p-value of the corresponding t-test.
Figure 5.
Robertsonian translocation t(13;17) affects SSC13 and SSC17 morphologies and localizations.
A–B. Chromosome paints for SSC13 (green) and SSC17 (red) were checked on metaphase spreads and 3D SpermFISH was performed on sperm nuclei. C. SSC13 and SSC17 chromosome territories (CT) were classified in three categories: colocalized when territories partially or completely merged together, adjacent when they are in close contact (but not merged) and distant. Sperm nuclei were classified in these three categories and their distribution tested between control and t(13;17) animals using a χ2 test. D. SSC13 and SSC17 CTs were classified regarding their round or elongated morphologies. For each chromosome, sperm nuclei were classified in these two categories and their distribution tested between control and t(13;17) animals using a χ2 test.
Figure 6.
Robertsonian translocation t(13;17) affects SSC13 localization along the medio-lateral axis.
A. Comparison of SSC13 and SSC17 distribution along the medio-lateral axis in control sperm nuclei. SSC13 is preferentially located at the periphery, close to the nucleus border while SSC17 is more uniformly distributed, from the periphery to the center of the nucleus. B. Comparison of SSC13 distribution along the medio-lateral axis in sperm nuclei from control (gold yellow) and t(13;17) (dark green) animals. SSC13 is displaced toward the center of the nucleus in presence of the t(13;17). Mean values for each condition are represented above the violin plot with the p-value of the corresponding t-test. C. Comparison of SSC17 distribution along the medio-lateral axis in sperm nuclei from control (gold yellow) and t(13;17) (dark green) animals. Mean values for each condition are represented above the violin plot with the p-value of the corresponding t-test.