Génomique, Epigénétique et Physiopathologie de la Reproduction, U1016 INSERM-UMR 8104 CNRS, Institut Cochin, Université Paris Descartes, Paris, France.
Laboratoire de Cytogénétique, Hôpital Cochin, APHP, 75014, Paris, France.
J Assist Reprod Genet. 2019 Jan;36(1):69-77. doi: 10.1007/s10815-018-1342-y. Epub 2018 Oct 25.
To explore the three-dimensional (3D) organization of sperm genome in DPY19L2-deficient globozoospermic patients speculating a link between DPY19L2 and genome organization of sperm nucleus.
This is a study of chromatin organization in DPY19L2-deficient globozoospermic patients and healthy donors using three-dimensional fluorescence in situ hybridization (3D-FISH) combined with confocal laser scanning microscopy followed by 3D image analysis. The 3D structures of sperm nuclei, chromocenter, telomeric regions and chromosome territories (CTs), were reconstructed using IMARIS software, and the relative radial position for each individual signal was calculated. Statistical analysis used a non-parametric Mann-Whitney test was appropriate with significance at p < 0.05.
DPY19L2-deficient globozoospermic patients display impaired sperm chromocenter organization resulting in an increased number of chromocenters (5.4 vs 3.5; p < 0.0001). Moreover, radial positions of telomeres are modified with a more central position in globozoospermic nuclei. 3D-FISH analysis of five chromosome territories (CTs) (X, Y, 7, 17, 18) showed that DPY19L2-deficient globozoospermic sperm nuclei display altered spatial organization of CT X, CT 7 and CT 18.
Our findings strengthen the hypothesis that DPY19L2 might be considered as a LINC-like protein having a crucial role in the organization of nuclear chromatin in sperm nucleus through its interaction with nuclear lamina. Our results might also explain defective embryonic development after intracytoplasmic sperm injection (ICSI) performed with DPY19L2-deficient globozoospermic sperm.
探索 DPY19L2 缺陷型圆头精子症患者精子基因组的三维（3D）结构，推测 DPY19L2 与精子核基因组组织之间的联系。
本研究采用三维荧光原位杂交（3D-FISH）联合共聚焦激光扫描显微镜及 3D 图像分析，对 DPY19L2 缺陷型圆头精子症患者和健康供者的染色质组织进行研究。使用 IMARIS 软件重建精子核、着丝粒、端粒区和染色体区室（CT）的 3D 结构，并计算每个信号的相对放射状位置。统计分析采用适当的非参数 Mann-Whitney 检验，具有统计学意义的 p 值为 <0.05。
DPY19L2 缺陷型圆头精子症患者的精子着丝粒组织受损，导致着丝粒数量增加（5.4 比 3.5；p < 0.0001）。此外，圆头精子核中端粒的放射状位置发生改变，更接近中心位置。对 5 个染色体区室（CT）（X、Y、7、17、18）的 3D-FISH 分析显示，DPY19L2 缺陷型圆头精子症患者的精子核中 CT X、CT 7 和 CT 18 的空间组织发生改变。
本研究结果进一步证实了 DPY19L2 可能作为一种 LINC 样蛋白，通过与核纤层相互作用，在精子核染色质组织中发挥重要作用的假说。我们的研究结果还可以解释用 DPY19L2 缺陷型圆头精子症患者的精子进行胞浆内单精子注射（ICSI）后胚胎发育不良的原因。
