| 摘要: |
| 采用细胞松弛素B(CB)处理,栉孔扇贝(Chlamys ferreri)抑制其受精卵的第一极体(PB1),研究抑制PB1对受精卵减数分裂过程及胚胎倍性组成的影响。结果发现,抑制第一极体显著改变了受精卵的染色体行为,在第二次减数分裂过程中共发现4种典型染色体分离类型,分别是三极分离(41.7%)、二极分离(11.7%)、双二极分离(24.9%)和非同步分离(2.8%),其余的受精卵(19.0%)染色体分离行为紊乱。对4-8细胞期胚胎的倍性组成进行分析,发现处理组中含有二倍体(10.9%)、三倍体(12.5%)、四倍体(19.5%)、五倍体(12.6%)以及非整倍体(46.6%)胚胎。研究结果表明,二极分离和双二极分离分别是形成三倍体和四倍体的主要机制,而其他的染色体分离行为将主要形成非整倍体。 |
| 关键词: 栉孔扇贝(Chlamys ferreri) 第一极体 染色体分离 胚胎 倍性组成 |
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| 基金项目:国家自然科学基金资助项目(30100141,30471326);国家 863 计划资助项目(2001AA628060);山东省博士基金资助项目(20000410) |
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| Effect of inhibiting the first polar body on chromosome segregation in fertilized eggs and ploidy composition of embryos in the zhikong scallop, Chlamys ferreri |
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| Abstract: |
| Effect of inhibiting the first polar body (PB1) on chromosome segregation in fertilized eggs and ploidy composition of 4～8 cell embryos was studied in Zhikong scallop, Chlamys ferreri. Cytochalasin B was applied to newly fertilized eggs to block the release of PB1. Four types of segregation were observed in meiosis II, namely， tripolar segregation (41.7%), bipolar segregation(11.7%), double bipolar segregation (24.9%) and unsynchronized segregation(2.8%). The remains could not be classified because of chromosome disorganization. In treated group, diploid (10.9%), triploid (12.5%), tetraploid (19.5%), pentaploid (12.6%) and aneuploid (46.6%) were found in 4～8 cell stage embryos. Results presented here indicate that bipolar segregation would lead to the formation of triploids. Tetraploids, however, are mainly resulting from double bipolar segregation. The remaining segregation would primarily produce aneuploids. |
| Key words: Chlamys ferreri the first polar body(PB1) chromosome segregation embryo ploidy composition |
