Embryogenesis is a progressive and complicated process that is regulated by differential gene activity. In order to identify some differentially expressed genes in early embryogenesis, two kinds of SMART cDNAs were respectively synthesized from mature eggs and gastrula embryos of Carassius auratus gibelio, and the gastrula embryo SMART cDNA library was constructed. Following this program, 131 positive clones were screened from about 1500 clones of the gastrula embryo SMART cDNA library by two rounds of dot-blot differential hybridizations using the synthesized SMART cDNAs as probes. Furthermore, 58 positive clones were selected for sequencing. Searching GenBank by the nucleotide sequences indicated that most of the sequenced cDNAs encoded ribosome proteins and regulators involved in translation and transcription, and some encoded lipoproteins involved in the metabolism of fat. And, some unknown new genes were also identified from the screening. Moreover, we investigated the expression patterns of 6 genes during embryogenesis by RT-PCR analysis, and confirmed their differential expression during embryogenesis. Four different expression patterns, such as transcribing again at gastrula based on the maternal products, beginning to transcribe at blastula stage, beginning to transcribe at gastrula stage, and transcribing only during embryogenesis, were revealed in the analyzed genes. Through this study, we cloned and identified some genes expressed differentially at early stage during embryogenesis, which will be a solid base for further researches on their functions and regulative mechanisms during embryogenesis.
Liu Jing-Xia; Shi Yao-Hua; Gui Jian-Fang (firstname.lastname@example.org).Screening of diefferentially expressed genes at gastrula stage during embryogenesis of Carassius auratus gibelio,Acta Hydrobiologica Sinica,2005,29(4):359-365