中文摘要：

收集2细胞、4细胞、8-16细胞时期的猪孤雌激活胚，采用SPEDDRT-PCR方法挑选不同时期的差异表达产物，通过反向Northern杂交去除假阳性的条带。将阳性条带克隆入T载体中，经过PCR鉴定后挑选其中的阳性克隆进行测序，筛选了8个代表不同时期表达差异的cDNA片段，编号为DD1-DD8。经过与GenBank中的数据进行同源性分析，发现其中DD1和DD2没有相似的数据，提交数据库获得GenBank登录号（EU545158，EU545159）；其余的DD3-DD8发现了相似性较高的数据，但除DD3外均无基因功能说明需要进行进一步的研究。

英文摘要：

The single preimplantation embryo differential display reverse transcription polymerase chain reaction （SPEDDRT-PCR） was used to identify differential genes in 2-cell, d-cell, 8-16-cell porcine parthenogenetic activated embryos. A total of 8 ESTs （ expressed sequences tags） were found using SPEDDRT-PCR and reverse northern dot blot, one of which in 2-cell ,four in 4-cell, and the other three in 8-16-cell embryo.All 8 ESTs were compared with nucleotide sequences deposited in the nr databasse and the dbEST database of Genbank using BLAST. DD3, DD4, DD5, DD6, DD7 and DD8 ESTs had their highly similar nucleotide sequences with ESTs existing in nucleotide databases but with unknown function. DD1 and DD2 ESTs had no significant similarity with exisiting genes or ESTs and were regarded as new ESTs. The two new ESTs were submitted to GenBank（ accession numbers： EU545158, EU545159 ）. This lays a foundation for further study on the mechanism of porcine preimplantation embtyo development.