Transcriptional and translational analysis of shrimp white spot syndrome virus structural protein gene wssv396

• Main Authors: Shih-Ting Kang, 康詩婷
• Other Authors: I-Chiu Liao
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/3dk7gg

碩士 === 國立臺灣大學 === 動物學研究研究所 === 93 === WSSV396, WSSV395 and WSSV394 are identified in pervious research as the three of thirty-nine structural proteins of shrimp white spot syndrome virus (WSSV). This study focuses on the transcriptional and translational analysis of wssv396, wssv395 and wssv394. The 3’RACE results reveal that wssv396, wssv395, and wssv394 share the same polyA tail. A common ~3.4-kb transcript, which is consistent with the predicted size of a polycistronic transcript encoding these three genes, was detected by using gene-specific probes respectively in northern blot analysis. Two primer sets were designed to generate two overlapping RT-PCR products to confirm the existence of the ~3.4-kb transcript, and the sequence data also indicated that the ~3.4-kb transcript is entire and intron-less. It reveals that wssv396, wssv395 and wssv394 are transcribed from the same promoter of wssv396. In the northern blot analysis, another ~1.6-kb transcript was recognized by wssv394-specific probe. According to the in vitro transcription and translation data, it could be concluded that WSSV396 and WSSV394 are translated from the ~3.4-kb and ~1.6-kb transcript by cap-dependent translation mechanism; the wssv395 is translated from the ~3.4-kb transcript by cap-independent translational mechanism. Based on the in vitro transcription and translation analysis of bicistronic constructs encoding wssv396 and wssv395, it suggests that the translational mechanism of wssv395 from the polycistronic transcript might occur by a mechanism using the internal ribosome entry site (IRES) on the upstream of the wssv396 ORF.