Jakobsen Anne S, Thomsen Preben D, Avery Birthe
Department of Large Animal Sciences, Veterinary Reproduction and Obstetrics, The Royal Veterinary and Agricultural University, Dyrlaegevej 68, 1870 Frederiksberg C, Denmark.
Theriogenology. 2006 Mar 1;65(4):870-81. doi: 10.1016/j.theriogenology.2005.06.014. Epub 2005 Aug 22.
Morphologically inferior bovine embryos developed in vivo have been shown by karyotyping to have a higher rate of chromosomally abnormal cells than morphologically normal embryos. The objective of this study was to re-examine this finding using interphase cytogenetics. A total of 155 IVP Day 8 bovine blastocysts were graded by their morphology (excellent, good, or poor) and timing of development (hatched, expanded, or non-expanded), and afterwards analysed for chromosome abnormalities by fluorescence in situ hybridization using differentially labelled probes for chromosomes 6 and 7. The overall frequency of diploid embryos was 7%, and did not differ according to grading. Although the frequency of mixoploidy was not correlated to the morphological grading, the blastocysts with excellent morphology displayed fewer polyploid nuclei in comparison to blastocysts with good (P=0.05) or poor morphology (P=0.01). There were however also prominent exceptions showing that a blastocyst with an excellent morphology can display a high degree of polyploidy. The results further demonstrate that the morphologically normal embryos contain a higher number of cells and develop more rapidly than the morphologically inferior embryos.
通过核型分析已表明，体内发育的形态较差的牛胚胎比形态正常的胚胎具有更高的染色体异常细胞率。本研究的目的是使用间期细胞遗传学重新审视这一发现。总共155个体外生产的第8天牛囊胚根据其形态（优秀、良好或较差）和发育时间（孵化、扩张或未扩张）进行分级，然后使用针对6号和7号染色体的差异标记探针通过荧光原位杂交分析染色体异常情况。二倍体胚胎的总体频率为7%，且根据分级没有差异。虽然混倍体频率与形态分级无关，但与形态良好（P = 0.05）或较差（P = 0.01）的囊胚相比，形态优秀的囊胚显示出较少的多倍体核。然而也有明显的例外情况，表明形态优秀的囊胚可以表现出高度的多倍体。结果进一步证明，形态正常的胚胎比形态较差的胚胎含有更多的细胞且发育更快。
