According to gene sequences, penaeidins (one kind of antibacterial peptide in shrimps) in genome of Chinese shrimp, Fenneropenaeus chinensis, could be assorted into three kinds. In order to explore the expression differences among-the three penaeidins after WSSV challenge, real-time quantitative PCR was used to detect the expression characteristics of these penaeidins at different time after WSSV challenge in Chinese shrimp. Shrimps used in the experiment came from the same parentage. After fed each individual the same dose of WSSV, 3-6 samples were collected at 0 h (uninfected), 6 h, 12 h, 24 h, 48 h, 72 h, 96 h, 120 h and 156 h after infection. The individuals dying in three days were regarded as WSSV-susceptive population, while those still living after seven days were regarded as anti-WSSV population. The results showed that the expression of penaeidins was tissue specific in four tissues of hepatopancreases, muscles, gills, and intestines, and the richness of expression and expression tendency from 0 h to 156 h was significantly different (P＜0.05). However, as far as one tissue was concerned, the tendency of expression for three penaeidins was similar in the period from 0 to 120 hours after challenge. For example, the expression of three penaeidins' mRNA in hepatopancreas was 0 at 0 h, and increased at 6-24 h, then decreased at 48-120 h, however increased again at 156 h. The results suggest that the three kinds of penaeidins have the similar biology function, though their DNA sequences were different from each other. Additionally, in order to study the correlation between penaeidins and anti-WSSV character, SNPs of each penaeidin were screened using PCR-SSCP. No significant correlation was found between SNPs and anti-WSSV or between SNPs and WSSV-susceptive shrimps (P＞0.05). It seemed that the penaeidins of shrimps might mainly take part in resisting bacteria, not in resisting WSSV.%通过白斑综合征病毒(WSSV)感染实验,利用实时定量PCR技术研究了中国明对虾(Fenneropenaeus chinensis)应答病毒侵染后,已知的3种抗菌肽(对虾肽)在肝胰腺、肌肉、肠和鳃4种组织中的差异表达情况.结果显示,虽然3种抗菌肽表现出明显的组织表达特异性,即在不同组织中的表达趋势和表达丰富度存在明显的差异,但是就同一个组织而言,3种抗菌肽在1～120 h WSSV侵染区间内的表达趋势基本一致,在0 h(未侵染病毒)时,3种抗菌肽的表达量极低(为0);在6～24 h期间,检测到明显的表达量;48～120 h期间,3种抗菌肽的表达量总体呈现下降的趋势.这暗示3种抗菌肽在对虾机体内可能具有相似的生物学功能.在此基础上,本研究对各类型中国明对虾抗菌肽的SNP位点进行了筛选,进一步对不同SNP类型与抗WSSV或易感WSSV的关联程度进行了分析,结果显示3种抗菌肽基因的SNP位点很少,且在抗性和易感对虾群体内不存在明显的偏向分布.
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