碩士 / 國立臺灣大學 / 動物學研究研究所 / 95 / Hyperthermia promotes survival of the WSSV-infected shrimps and the underlying mechanisms remain unknown. In the present study, we investigated the effects of hyperthermia (25 vs. 32℃) on WSSV gene expression and genome replication in Penaeus monodon shrimp. By using IQ2000 kits, we found that high level of WSSV genome could be detected as early as 12 hours post infection (hpi.) at 25℃, whereas low amount of WSSV genome became detectable until 48 hpi. at 32℃. Temporal analyses of the transcription of several WSSV genes showed that although high infection temperature did not affect the transcription pattern of a latency-associated gene (wssv194), the patterns of two immediate early genes (ie1 and ie2) and the early gene dna polymerase (dna pol) changed dramatically. At 25℃, the expression level of ie1, ie2 and dna pol was low at 2 – 8 hpi., and gradually increased at 12 – 48 hpi. At 32℃, the expression of these three genes surged rapidly to reach a high level by 2 hpi. and then maintained at a constant level until the end of the analysis. The expression of two viral proteins, IE1 and VP28, was investigated using Western blot analysis, and it showed that at 25℃ both proteins were detected at 24 and 48 hpi., but at 32℃, neither proteins were identified. Based on these studies, we concluded that at high infection temperature (32℃), WSSV’s transcription activity was aberrantly high, its replication was blocked and the amount of viral proteins was quite low. STATs up-regulates ie1 gene expression. In the present study, Western blot analysis showed that in normal shrimp, hyperthermia activated STATs, and this might explain in part how ie1 transcription was induced by hyperthermia. Lastly, the protein profile changes in WSSV-infected shrimp induced by hyperthermia were analysed using two-dimensional gel electrophoresis coupled with mass spectrometry. Two shrimp proteins, NAD-dependent aldehyde dehydrogenases and proteasome alpha 4 subunit, were upregulated significantly. The increased expression of a proteasome-related protein suggested that in WSSV-infected shrimp, hyperthermia might enhance the protein degradation pathway to down-regulate viral protein expression.
| Identifer | oai:union.ndltd.org:TW/095NTU05312019 |
| Date | January 2007 |
| Creators | Hsiao-Chun Hung, 洪曉君 |
| Contributors | , 郭光雄, 羅竹芳 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 55 |
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