Tateno Hiroyuki, Kamiguchi Yujiroh
Department of Biological Sciences, Asahikawa Medical College, Asahikawa 078-8510, Japan.
Biol Reprod. 2007 Aug;77(2):336-42. doi: 10.1095/biolreprod.106.057778. Epub 2007 Apr 4.
To investigate whether cytogenetic risks occur using the mouse intracytoplasmic sperm injection (ICSI) technique, the incidence of chromosome aberrations was compared in one-cell embryos produced by ICSI technique and those by conventional in vitro fertilization (IVF) technique. Spermatozoa were incubated in TYH medium for 1.5-2 h before IVF insemination. For the ICSI technique, spermatozoa were incubated in five different media: TYH, Hepes-buffered TYH (H-TYH), modified CZB (mCZB), Hepes-buffered mCZB (H-mCZB), and PB1 for 0.5 h, 2-2.5 h, and 6 h before injection into metaphase II oocytes. The incidence of IVF embryos with structural chromosome aberrations was 2%, whereas the occurrence of structural chromosome aberrations in ICSI embryos was dependent on the kind of medium and sperm incubation time. When spermatozoa were incubated in TYH medium for 2 h or more, the aberration rates in the resultant ICSI embryos (4%) were not significantly different from that of IVF embryos. However, there was a significant increase in aberration rates in ICSI embryos derived from spermatozoa that were incubated in other culture conditions (6%-28%). In addition, a time-dependent increase in aberration rates was found in ICSI embryos when H-TYH, H-mCZB, and PB1 were used for sperm incubation. There was no significant difference in incidence of aneuploidy between IVF and ICSI embryos. The chromosome analysis results of one-cell embryos were reflected by the performance of postimplantation embryo development. The causal mechanism of chromosome damage in ICSI embryos was discussed in relation to the plasma membrane cholesterol, the acrosome, and in vitro aging of spermatozoa.
为了研究使用小鼠胞浆内单精子注射（ICSI）技术是否会产生细胞遗传学风险，比较了通过ICSI技术产生的单细胞胚胎与通过传统体外受精（IVF）技术产生的单细胞胚胎的染色体畸变发生率。在IVF授精前，将精子在TYH培养基中孵育1.5 - 2小时。对于ICSI技术，在将精子注射到中期II卵母细胞之前，分别在五种不同的培养基中孵育：TYH、Hepes缓冲的TYH（H - TYH）、改良CZB（mCZB）、Hepes缓冲的mCZB（H - mCZB）和PB1，孵育时间分别为0.5小时、2 - 2.5小时和6小时。IVF胚胎中结构染色体畸变的发生率为2%，而ICSI胚胎中结构染色体畸变的发生取决于培养基的种类和精子孵育时间。当精子在TYH培养基中孵育2小时或更长时间时，所得ICSI胚胎的畸变率（4%）与IVF胚胎的畸变率无显著差异。然而，在其他培养条件下孵育的精子所产生的ICSI胚胎中，畸变率显著增加（6% - 28%）。此外，当使用H - TYH、H - mCZB和PB1进行精子孵育时，ICSI胚胎中的畸变率呈现时间依赖性增加。IVF和ICSI胚胎之间非整倍体的发生率没有显著差异。单细胞胚胎的染色体分析结果反映在植入后胚胎发育的表现上。结合质膜胆固醇、顶体和精子的体外老化，讨论了ICSI胚胎中染色体损伤的因果机制。
