热激条件下家蚕杂交组合及其亲本品种血液免疫应激相关蛋白质的差异表达分析

Analysis on Differential Expression of Immune Response Related Proteins in Haem olymph of Silkworm Hybrid Com bination and Its Parental Varieties After Heat Shock Treatment

以家蚕品种秋丰(Q)、白玉(B)及其杂交组合秋丰×白玉(QB)为试验材料,利用双向电泳和质谱技术研究40℃热激处理对家蚕幼虫血液蛋白质组的影响,分析热激处理后亲本品种和杂交组合血液免疫相关蛋白的表达差异。在双向电泳图谱显示的供试家蚕品种及其杂交组合分离较好的蛋白点中,有87.67%的蛋白点表现为加性效应(additivity)的表达模式,7.15%的蛋白点表现超显性(over-dominance)表达模式,5.17%的蛋白点表现为超隐性(under-dominance)表达模式。对25个差异表达的蛋白点进行质谱鉴定,根据基因注释有7个蛋白点与免疫应激有关。在短时间的高温刺激后,热激关联蛋白(h2)、肽聚糖识别蛋白(h25)、亲环素样蛋白(h26)、促进蛋白(h27)和载脂蛋白Ⅲ(h28)等5个蛋白点在2个亲本品种及其杂交组合的幼虫血液中均呈现上调表达趋势,尤其是杂交组合与2个亲本品种相比上调表达更为显著。研究结果表明,家蚕在热激条件下,短时间内可以通过提高免疫系统的应激能力以增强自身对环境胁迫的耐受性,而且杂交组合与亲本品种相比在抗逆性方面表现突出,对高温刺激更加敏感,这也在一定程度上揭示了家蚕的抗逆性存在杂种优势。

In present study,silkworm（ Bombyx mori） varieties Qiufeng（ Q） and Baiyu（ B） and their hybrid combination Qiufeng × Baiyu（ QB） were used as materials to study the impact of 40 ℃ heat shock treatment on hemolymph proteome of silkworm larvae. The differential expression of immune response related proteins in haemolymph between parent varieties and hybrid combination after heat shock treatment was analyzed by using two-dimensional electrophoresis（ 2D） and mass spectrometry. Among the protein spots obviously separated in 2D-PAGE pattern,87. 67%,7. 15% and 5. 17% ofthem showed additivity, over-dominance and underdominance expression patterns,respectively. Twenty-five differentially expressed protein spots were identied by peptide mass ngerprinting,among which seven protein spots are related to immune response. After heat shock treatment for a short time,5 proteins including heat shock cognate protein（ h2）,peptidoglycan recognition protein（ h25）,cyclophilin-like protein（ h26）,promoting protein（ h27） and apolipophorin Ⅲ（ h28） showed obviously up-regulated trend in hemolymph of these two parental varieties and their hybrid combination. Especially,the expression level of these proteins in hemolymph of the hybrid combination was signicantly higher than those of the two parental varieties.These findings suggested that after heat shock treatment,silkworm tolerance against environmental stress was enhanced by increasing the ability of the immune system in a short period of time. Moreover,the hybrid combination had relatively higher resistance than parental varieties and was more sensitive to high temperature,indicating to some extent that there was heterosis in the resistance of silkworm.