比較石斑魚苗在感染神經壞死症病毒前後寄主基因表現之差異

Abstract

神經壞死症病毒（Nervous Necrosis Virus, NNV ）在感染石斑魚苗後，會引起急性發病及大量死亡。本研究目的在找出因NNV感染而表現量有明顯差異的寄主基因，並觀察這些基因表現量在感染病毒後的時序變化。採收NNV感染前後的石斑魚苗的mRNA，用抑制性雜合扣除法（Suppression Subtractive Hybridization, SSH），以及北方雜合法（Northern analysis）篩選出四株在感染NNV前後有差異表現量的寄主基因，這些基因序列經由Blast-n比對後，由正向扣除所篩選的FB2序列是alpha-microglobulin/HI-30 precursor，FB9序列是glyceraldehyde 3-phosphate dehydrogenase（G3PDH），在反向扣除所篩選到的R1H1序列是beta globin，R2H12是liver-basic fatty acid binding protein（Lb-FABP）。比較這四個基因於NNV感染後不同天數的表現量，發現代號為FB2及FB9的兩個基因，在感染末期的瀕死魚體內表現量激增；而代號為R1H1及R2H12的兩個基因，則在感染後表現量驟減。

Nervous Necrosis Virus（NNV）can induce acute infection and mass mortality of grouper fry and larva. The aim of this study is to detect and analysis of the differentially expressed grouper genes after NNV infection. By suppression subtractive hybridization (SSH) and Northern analysis, two cDNA sequences（FB2, FB9） were selected by forward subtraction and two cDNA sequences（R1H1, R2H12）were selected by reverse subtraction. These four cDNA sequences were analyzed by Blast-n program, and the results revealed that FB2 is similar to the gene of alpha-microglobulin/HI-30 precursor, FB9 is similar to the gene of glyceraldehyde 3-phosphate dehydrogenase (G3PDH), R1H1 is similar to the gene of beta globin, and R2H12 is similar to the gene of liver-basic fatty acid binding protein (Lb-FABP). The expression of either FB2 and FB9 increased significantly in the moribund fish 9 days after NNV infection. On the other hand, the expression of R1H1 and R2H12 decreased drastically in the fish showing clinical syndrome of NNV disease in the early stage of NNV infection.