Shibasaki Ikue, Sugiyama Hinata, Kamada Yuko, Nagatomo Hiroaki, Ito Daiyu, Wakayama Sayaka, Ooga Masatoshi, Kasai Tsuyoshi, Kohda Takashi, Wakayama Teruhiko
Faculty of Life and Environmental Sciences, University of Yamanashi, Yamanashi, Japan.
Konohana Clinic, Kai, Japan.
Commun Biol. 2025 Jan 9;8(1):6. doi: 10.1038/s42003-024-07358-0.
Abnormal chromosome segregation (ACS) in preimplantation embryos causes miscarriages. For a normal pregnancy, it is necessary to reduce ACS occurrences in embryos. However, the causes of such abnormalities are unclear because no method to extract the segregated chromosomes from the blastomeres for detailed analysis. This study attempted to extract micronuclei derived from segregated chromosomes of mouse embryos. Some micronuclei in blastomeres were bound to the nucleus by DNA cross-links, some were bound to tubulin, and about half of the micronuclei had major satellite regions. By depolymerizing the cytoskeleton of blastomeres with cytochalasin B and colcemid, some micronuclei could be extracted from blastomeres of ACS embryos using a glass needle of a micromanipulator. DNA-sequencing results of each extracted micronucleus revealed that chromosomes in micronuclei were randomly selected, usually only one, and often contained a portion rather than the full length of the chromosome. This study allows a detailed analysis of micronuclei and facilitates the mechanism of the causes of ACS in embryos.
植入前胚胎中的染色体异常分离（ACS）会导致流产。对于正常妊娠而言，减少胚胎中ACS的发生是必要的。然而，此类异常的原因尚不清楚，因为没有方法从卵裂球中提取分离的染色体进行详细分析。本研究试图从小鼠胚胎分离的染色体中提取微核。卵裂球中的一些微核通过DNA交联与细胞核结合，一些与微管蛋白结合，并且约一半的微核具有主要卫星区域。通过用细胞松弛素B和秋水仙酰胺使卵裂球的细胞骨架解聚，使用显微操作器的玻璃针可从ACS胚胎的卵裂球中提取一些微核。对每个提取的微核进行DNA测序的结果显示，微核中的染色体是随机选择的，通常只有一条，并且常常包含染色体的一部分而非全长。本研究能够对微核进行详细分析，并有助于了解胚胎中ACS的成因机制。
