Chromosomal abnormalities in day-6, in vitro-produced pig embryos
Chromosomal abnormalities in day-6, in vitro-produced pig embryos
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DOI：
10.1016/s0093-691x(03)00172-9
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发表时间：
2003-11-01
期刊：
影响因子：
2.8
通讯作者：
Day, BN
中科院分区：
文献类型：
--
作者：
McCauley, TC;Mazza, MR;Day, BN
通过细胞遗传学研究，通过染色体核型分析，对猪体外受精(IVP)胚胎第6天染色体异常的发生率和类型进行了量化。将形态正常的第6天囊胚(n=318)按细胞总数分为6类(小于或等于20个到61-70个)。在248个适合分析的胚胎中，97个(39.1%)出现了染色体异常。异常类型包括单倍体(9.3%)、多倍体(71.1%)和混倍体(19.6%)。在多倍体胚胎中，三倍体和四倍体的出现率最高(分别为56.5%和27.5%)，在混倍体胚胎中，二倍体三倍体胚胎(2n/3n)最多(36.8%)。总体上，平均细胞数为34.3+/-12.1，分裂指数为8.6+/-6.1。染色体异常胚胎的总细胞数(P<；0.01)少于正常胚胎(31.8+/-1.3比35.9+/-1.0)。此外，随着细胞数目的增加，多倍体的发生率降低，而混倍体的发生率没有差异。这些数据表明，多倍体影响了很大比例的能够发育到囊胚的体外受精-胚胎，染色体异常的发生率远远高于该物种体内胚胎的报道。考虑到染色体异常的形态正常胚胎在体外可以进行着床前发育，以及在没有细胞遗传学分析的情况下无法识别核型异常的囊胚，在评估猪体外胚胎生产方案时，应该仔细考虑影响体外受精胚胎倍性的因素，特别是多精受精的发生率。(C)2003 Elsevier Inc.保留所有权利。
A cytogenetic study was undertaken to quantify, by chromosomal karyotyping, the incidence and type of chromosomal abnormalities present in Day-6 in vitro-produced (IVP) porcine embryos. Morphologically normal Day-6 blastocysts (n = 318) were fixed and grouped into six classes according to the number of total cells (from less than or equal to20 to 61-70). Of 248 embryos suitable for analysis, 97 (39.1%) displayed chromosomal abnormalities. The abnormalities included haploidy (9.3%), polyploidy (71.1%) and mixoploidy (19.6%). Within polyploid embryos, triploidy and tetraploidy showed the highest incidence (56.5 and 27.5%, respectively); among mixoploid embryos, diploidtriploid embryos (2n/3n) were prevalent (36.8%). Overall, the mean cell number was 34.3 +/- 12.1 and the mitotic index was 8.6 +/- 6.1. Chromosomally abnormal embryos had fewer (P < 0.01) total cells compared to normal (2n) embryos (31.8 +/- 1.3 versus 35.9 +/- 1.0). In addition, the incidence of polyploidy decreased as the number of cells increased, while that of mixoploidy did not differ. These data indicate that polyploidy affects a large percentage of IVP porcine embryos capable of developing to blastocysts and the incidence of chromosomal abnormalities is much higher than that reported previously in in vivo embryos in this species. Given the ability of morphologically normal embryos with an abnormal chromosome complement to undergo preimplantation development in vitro, and the inability to identify blastocysts with abnormal karyotype without cytogenetic analysis, careful consideration should be given to factors affecting ploidy of IVP embryos, especially the incidence of polyspermic fertilization, when evaluating criteria of a porcine in vitro embryo production scheme. (C) 2003 Elsevier Inc. All rights reserved.