家蚕脂肪酶基因Bmlipase-1在不同BmNPV抗性水平家蚕品种间的表达差异

Differential Expression of Bmlipase-1 Gene in Bombyx mori Varieties with Different Resistance Levels Against BmNPV

家蚕脂肪酶Bmlipase-1在家蚕中肠组织特异性表达,具有抵抗家蚕核型多角体病毒(BmNPV)感染的活性。以对BmNPV具有不同抗性水平的6个家蚕品种为材料,利用荧光定量PCR(qRT-PCR)技术,检测Bmlipase-1基因在不同家蚕品种5龄期健康幼虫中肠组织的表达水平及感染BmNPV后的5龄期幼虫中肠组织中该基因的表达水平变化,探究该基因表达水平与家蚕对BmNPV的抗性水平的关系。结果表明:不同家蚕品种间Bmlipase-1的表达水平差异显著,抗性较强的品种,其表达水平较高,6个供试品种5龄幼虫中肠组织中的Bmlipase-1表达水平依次为NIL.LVR>P50>CVDAR18>nsd.NIL>892>306,抗性较强品种NIL.LVR 5龄期的平均表达量约为抗性较弱品种306的8.2倍;BmNPV能够诱导Bmlipase-1的表达,但不同品种间该基因的诱导表达差异显著,仍表现为抗性较强的品种该基因的诱导表达水平较高,NIL.LVR经BmNPV感染诱导后Bmlipase-1在5龄期的平均表达量约为抗性较弱品种306平均诱导表达水平的12.4倍。推测Bmlipase-1的表达水平与蚕体自身对BmNPV的抗性水平有一定的关联性。

Silkworm （ Bombyx mori） lipase 1 （Bmlipase-1） is specifically expressed in midgut of silkworm larvae, conferring the larvae with resistance against Bombyx mori nucleopolyhedrovirus （BmNPV） infection. Using 6 silkworm varieties with different resistance levels against BmNPV as materials, the expression levels of Bmlipase-1 in midguts of healthy lar-vae and BmNPV-infected larvae of the 5th instar from different silkworm varieties were detected to explore the relation-ship between expression level of Bmiipase-1 and resistance level of silkworm to BmNPV by fluorescent quantitative PCR （qRT-PCR） technology. The results showed that the expression level of Bmlipase-1 had significant difference in different silkworm varieties. The expression level was higher in silkworm varieties with stronger viral resistance. Expression levels of Bmlipase-1 of the 6 tested silkworm varieties were in the order of NIL. LVR 〉P50 〉CVDAR18 〉nsd.NIL 〉892 〉306. The average expression level of Bmlipase-1 in the 5th instar of the highly resistant variety NIL. LVR was about 8.2 times to that of the lowly resistant variety 306. Expression of Bmlipase-1 gene could be in- duced by BmNPV infection, and the induced expression levels were significantly different in different silkworm varieties. The induced expression level of Bmlipase-1 was also higher in silkworm varieties with stronger viral resistance. After infection by BmNPV, the average expression amount of Bmlipase-1 in the 5th instar of NIL.LVR was about 12.4 times to that of 306, the variety with the lowest resistance. It is suggest that there is certain relevance between expression level of Bmlipase-1 and the resistance level of silkworm against BmNPV.