Schmiady H, Tandler-Schneider A, Kentenich H
Virchow-Klinikum, Medizinische Fakultät, Humboldt-Universität zu Berlin, Germany.
Hum Reprod. 1996 Oct;11(10):2239-45. doi: 10.1093/oxfordjournals.humrep.a019083.
A cytogenetic-cytological study was performed on unfertilized human oocytes (first polar body visible) after intracytoplasmic sperm injection (ICSI) with respect to the rate of prematurely condensed sperm chromosomes (G1-PCC). Out of 163 prepared oocytes derived from 41 ICSI cycles, 133 (approximately 82%) could be analysed successfully. a total of 60 oocytes (45.1%) showed metaphase II chromosomes in the haploid range along with an intact sperm head and 27 oocytes (20.3%) were missing the sperm head, but two of them showed an approximately diploid set of chromosomes; 38 oocytes (28.4%) exhibited the maternal metaphase II chromosomes as well as G1-PCC of the sperm nucleus showing a remarkable variation in the degree of condensation. Ten ICSI cycles (each followed by an embryo transfer) were characterized each by 2-3 oocytes demonstrating G1-PCC. It is concluded that the main cause of failed fertilization after ICSI is the failure of oocyte activation. When the sperm nucleus is able to act with the chromosome condensing factors and the oocyte does not become activated, this will lead to the induction of PCC. Absence of the sperm head might be due to injection or ejection of the spermatozoon in the perivitelline space except for two cases in which fertilization might have occurred. Finally, the observation of both a single chromatin region (n = 6) or two chromatin regions (n = 2) indicated oocyte activation which, however, was followed by developmental arrest.
对卵胞浆内单精子注射（ICSI）后未受精的人类卵母细胞（可见第一极体）进行了细胞遗传学-细胞学研究，以观察过早凝聚精子染色体（G1-PCC）的发生率。在来自41个ICSI周期的163个准备好的卵母细胞中，133个（约82%）能够成功分析。总共60个卵母细胞（45.1%）显示处于单倍体范围的中期II染色体以及完整的精子头部，27个卵母细胞（20.3%）没有精子头部，但其中两个显示出近似二倍体的染色体组；38个卵母细胞（28.4%）表现出母源性中期II染色体以及精子细胞核的G1-PCC，其凝聚程度有显著差异。十个ICSI周期（每个周期随后进行胚胎移植）每个周期都有2-3个显示G1-PCC的卵母细胞。得出的结论是，ICSI后受精失败的主要原因是卵母细胞激活失败。当精子细胞核能够与染色体凝聚因子相互作用而卵母细胞未被激活时，这将导致PCC的诱导。除了两例可能发生受精的情况外，精子头部缺失可能是由于精子注射到卵周间隙或从卵周间隙中排出。最后，观察到单个染色质区域（n = 6）或两个染色质区域（n = 2）表明卵母细胞已激活，然而，随后出现了发育停滞。
