CyHV-3感染镜鲤选育世代免疫基因表达及抗病能力比较

Comparisons of the immune gene expression and disease resistance between mirror carp breeding generations after CyHV-3 infection

摘要:

对镜鲤抗锦鲤疱疹病毒（CyHV-3）新品种的选育工作，目前已经进行到F₃，F₂、F₃成活率相近且显著高于F₁。本研究利用实时荧光定量PCR技术比较选育世代间免疫基因IL-1β、TRAF6、MyD88a、I-IFN和TLR7a的表达及CyHV-3病毒载量情况，从而在免疫基因表达水平及病毒载量两个方面结合抗病成活率综合评估选育世代的抗病能力。结果显示：（1）CyHV-3病毒载量在F₁、F₂、F₃中呈下降趋势，且F₃显著低于F₁、F₂（P<0.05）；（2）夏花组未感染CyHV-3，仅TRAF6基因在F₃的表达显著高于F₁、F₂（P<0.05）；（3）感染组F₃脾中IL-1β、MyD88a基因显著高于F₁、F₂（P<0.05）、TRAF6显著高于F₁（P<0.05），F₃肾中IL-1β、TRAF6基因显著高于F₁、F₂（P<0.05），F₁与F₂间均差异不显著（P>0.05）。以上结果说明在选育世代间除TRAF6基因表达较高外，其他基因未受选育影响，且F₃抗病能力显著高于F₁、F₂。基于F₂、F₃成活率相近且显著高于F₁，说明F₂抗病力不稳定，而F₃抗病力已趋于稳定，也说明从免疫基因表达或病毒载量方法进行抗病能力评估是可行的。

关键词:镜鲤;锦鲤疱疹病毒3型;免疫基因;病毒载量;抗病力评估

Abstract:

The mirror carp breeding of generations targeted at Koi herpes virus (CyHV-3) has been carried out to F₃ generation. F₂ and F₃ survival rates are similar and significantly higher than F₁. In this study, theCyHV-3 viral loads and the gene expression of IL-1β, TRAF6, MyD88a, I-IFN and TLR7a are compared by real-time fluorescence quantitative PCR technique. Immune gene expression levels and viral loads in combination with disease resistance survival rates are used to evaluate the disease resistance of different generations. The results showed that: (1) CyHV-3 virus load decreased sequentially in F₁, F₂ and F₃, and F₃ was significantly lower than F₁ and F₂ (P<0.05); (2) Summerlings group wasn't infected CyHV-3, only the expression of TRAF6 gene in F₃ was significantly higher than that in F₁ and F₂ (P<0.05). (3) In the infected group, the levels of IL-1β and MyD88a in F₃ spleen were significantly higher than those in F₁ and F₂ (P<0.05), and TRAF6 was significantly higher than that of F₁ (P<0.05). The expression of IL-1β and TRAF6 in F₃ kidney was significantly higher than that in F₁ and F₂ (P<0.05). There was no significant difference between F₁ and F₂ (P>0.05). The above results show that F₃ disease resistance is significantly higher than F₁, F₂, only the TRAF6 gene was breeding. Based on the fact that F₂, F₃ survival rate was similar and significantly higher than F₁, it can be concluded that F₂ disease resistance is not stable and F₃ resistance has stabilized, and that using the immune gene expression or viral load method to evaluate the disease resistance is feasible.

Key words:mirror carp;koi herpes virus 3;immune gene;viral load;disease resistance assessment