Yang Qingling, Zhang Nan, Zhao Feifei, Zhao Wanli, Dai Shanjun, Liu Jinhao, Bukhari Ihtisham, Xin Hang, Niu Wenbing, Sun Yingpu
Reproductive Medical Center, First Affiliated Hospital of Zhengzhou University, China.
School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, China.
Reprod Biomed Online. 2015 Jul;31(1):44-50. doi: 10.1016/j.rbmo.2015.02.016. Epub 2015 Mar 27.
The ends of eukaryotic chromosomes contain specialized chromatin structures called telomeres, the length of which plays a key role in early human embryonic development. Although the effect of sperm preparation techniques on major sperm characteristics, such as concentration, motility and morphology have been previously documented, the possible status of telomere length and its relation with sperm preparation techniques is not well-known for humans. The aim of this study was to investigate the role of density gradient centrifugation in the selection of spermatozoa with longer telomeres for use in assisted reproduction techniques in 105 samples before and after sperm processing. After density gradient centrifugation, the average telomere length of the sperm was significantly longer (6.51 ± 2.54 versus 5.16 ± 2.29, P < 0.01), the average motile sperm rate was significantly higher (77.9 ± 11.8 versus 44.6 ± 11.2, P < 0.01), but average DNA fragmentation rate was significantly lower (11.1 ± 5.9 versus 25.9 ± 12.9, P < 0.01) compared with raw semen. Additionally, telomere length was positively correlated with semen sperm count (rs = 0.58; P < 0.01). In conclusion, density gradient centrifugation is a useful technique for selection of sperm with longer telomeres.
真核染色体的末端含有称为端粒的特殊染色质结构，其长度在人类早期胚胎发育中起关键作用。尽管精子制备技术对精子主要特征（如浓度、活力和形态）的影响先前已有文献记载，但端粒长度的可能状态及其与精子制备技术的关系在人类中尚不清楚。本研究的目的是调查密度梯度离心在105份精子处理前后样本中选择端粒较长的精子用于辅助生殖技术中的作用。密度梯度离心后，精子的平均端粒长度显著更长（6.51±2.54对5.16±2.29，P<0.01），平均活动精子率显著更高（77.9±11.8对44.6±11.2，P<0.01），但平均DNA碎片率显著更低（11.1±5.9对25.9±12.9，P<0.01），与未处理精液相比。此外，端粒长度与精液精子计数呈正相关（rs = 0.58；P<0.01）。总之，密度梯度离心是一种选择端粒较长精子的有用技术。
