中文摘要：

以龙眼体胚发生早期的胚性培养物为材料，通过简并引物结合PCR进行eDNA末端快速克隆（RACE）的技术，克隆到了龙眼体胚相关未知蛋白基因DIUP-5全长序列，其eDNA全长为887bp，由681个核苷酸组成的开放阅读框，编码226个氨基酸（GenBartk登陆号为GQ443759）．该基因推导的蛋白分子质量为24511．9u，理论等电点pI为9．65；该蛋白是Frigl-da-like蛋白质家族成员，是一个具有Ffiglda组件，无典型信号肽结构，无跨膜螺旋的亲水性蛋白；不规则卷曲是其最大量的结构元件，并且主要集中在C端区域．实时荧光定量PCR分析结果显示，该基因在龙眼体胚发生过程中均有表达，呈“N”形趋势，其中以不完全胚性紧实结构阶段最高，而鱼雷形胚阶段表达量最低；方差分析表明，鱼雷形胚阶段DIUP-5基因表达量与其他7个阶段存在极显著差异．该研究结果对DIUP-5基因在龙眼体胚发生过程中的作用有了一个初步的认识，其在龙眼胚性愈伤组织胚胎发生能力、早期体胚正常发育和体胚成熟过程等方面可能起重要作用．

英文摘要：

The full-length sequence of the gene DlUP-5 （ Dimocarpus longan unknown protein gene 5） from embryogenic cultures was obtained by using degenerate oligonueleotide primers together with rapid amplification of eDNA ends （RACE） technique. The full-length eDNA sequence of DIUP-5 gene is 887 bp. It contained a 681-nucleotides-long open reading frame （ORF） which enco- ded a protein of 226 amino acid residues （GenBank No. GQ443759）. Bioinformatics analysis showed that the molecular weight of DIUP-5 protein was 24511.9 u with pI value 9.65. The protein, including a Frigida module, belongs to Friglda-like family. It has hydrophilic characteristics and no transmembrane properties as well as no signal peptide. Random coils are the most maximum struc- tural elements in it and were found mainly concentrating in the C terminal domain. The expression of DlUP-5 gene was also observed during longan somatic embryogenesis. Its expression trend was ＂N＂ shape, the highest expression level occurred at incomplete com- pact pro-embryogenic cultures stage, and the lowest appeared at torpedo embryos stage. The variance analysis results showed that the relative mIt.NA transcription levels of DIUP-5 at torpedo embryos stage was significantly higher than those at the other seven sta- ges. It shaded light on the result suggest that the DIUP-5 gene has some important functions during longan somatic embryogenesis. According to the transcription level change of DIUP-5, it may play some important functions in maintaining high embryogenesis com- petence of longan embryogenic callus and facilitate further development and growth of embryos. This result laid a foundation for the further study on the function of DtUP-5 gene during longan somatic embryogenesis.