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在人类染色体中期制片中,D组和G组近端着色粒染色体常联合在一起,叫随体联合(sa),随体联合最常发生于21号和13号染色体之间,其次在21和14之间。 sa可能是人类染色体异常的原因,已知活产婴儿中的主要染色体异常涉及近端着丝粒染色体,这些异常包括由不分离和易位引起的非整倍体。近端着丝粒染色体参与sa使它们容易发生不分离、DNA交换和重排。多个小核仁融合成一个大核仁把近端着丝粒染色体在减数分裂和有丝分裂期间拉在一起形成sa,这就增加不分离的危险。减数分裂和有丝分裂期间sa频率的增加可能会导致不分
In the metaphase of human chromosomes, proximal chromosomal chromosomes of groups D and G are often combined together, called satellite association (sa), and satellite association most often occurs between chromosomes 21 and 13, followed by 21 And 14 between. sa may be the cause of human chromosomal abnormalities. It is known that major chromosomal abnormalities in live-born infants involve the proximal centromeric chromosomes, including aneuploidies caused by non-segregation and translocation. Proximal centromeric chromosomes involved in sa make them prone to non-separation, DNA exchange and rearrangement. The fusion of multiple small nucleoli into a large nucleus pulls near the centromeric chromosomes during meiosis and mitosis to form sa, which increases the risk of non-segregation. The increase of sa frequencies during meiosis and mitosis may lead to indifference