全龄人工饲料育与桑叶育家蚕生丝的蛋白质成分比较

Comparative Analysis of Protein Composition of Raw Silk from Silkworm Reared on Artificial Diet and Mulberry Leaf in All Instars

实现家蚕全龄人工饲料育是未来蚕业发展的主攻方向之一。尽管已经有商业化的家蚕人工饲料,但很多家蚕品种不适宜全龄人工饲料育。本课题组通过长期的人工饲料育选择,培养出了适宜人工饲料育的家蚕品种桂蚕5号,并已经在生产上推广。为了解桂蚕5号全龄人工饲料育蚕茧缫丝后生丝品质是否与桑叶育有差异,对全龄人工饲料育家蚕生丝(SL)和桑叶育家蚕生丝(SY)进行蛋白质成分的比较分析;同时,辅以6A级生丝作为高品质生丝对照。结果表明,3个样品检测到共有蛋白242种,SL含有特有蛋白15种,SY含有13种,6A级生丝含有13种,主要为一些低丰度蛋白。对共有蛋白进行含量差异分析,结果显示,SL与SY的差异蛋白总共只有20种,SL与6A级生丝的差异蛋白有14种。对LFQ强度值排名前20的蛋白质进行分析发现,主要是丝素蛋白、丝胶蛋白、类P25蛋白及未知功能蛋白,与已经报道的结果基本一致。而且,SL的丝素蛋白、丝胶蛋白含量与SY和6A级生丝相比都没有显著差异。利用丝蛋白抗体对3种生丝的丝胶和丝素蛋白进行Western blot验证,发现丝素蛋白Fib-L和P25以及丝胶蛋白Ser1和Ser3在3种生丝中的信号强度基本一致,但在SL中检测到了强烈的Ser2蛋白信号,由于Ser2为非茧丝蛋白,推测其对生丝的性能没有大的影响。综上所述,桂蚕5号进行全龄人工饲料育所缫制生丝的蛋白质成分含量与桑叶育生丝及6A级生丝没有显著差异,具有替代桑叶育所缫制生丝用于后期高品质茧丝制品开发和应用的潜能。

To realize the artificial diet rearing for all instars of silkworm is one of the main direction for the development of the sericulture industry in the future. Although there are commercialized artificial diet for silkworm, many silkworm varieties are not suitable for artificial diet rearing in all instars. Through long-term selection of artificial diet breeding, our group obtained a silkworm variety Guican 5, which is suitable for artificial diet rearing, and has been popularized in production. In order to know whether the quality of raw silk of Guican 5 raised by artificial diet is different from that raised by mulberry leaves, the protein components of raw silk were compared and analyzed between artificial diet rearing cocoon(SL) and mulberry leaf rearing cocoon(SY). Meanwhile, 6 A grade raw silk was used as a high-quality raw silk control. The results showed that 242 shared proteins were detected in these three samples, 15 specific proteins in SL, 13 in SY and 13 in 6 A raw silk, mainly some low abundance proteins. The content difference analysis of the shared proteins showed that there were only 20 differential proteins between SL and SY, while 14 between SL and 6 A raw silk. The analysis of the top 20 proteins with LFQ intensity value found that they were mainly silk fibroin, sericin, P25-like proteins and unknown proteins, which were consistent with the reported results. Moreover, the silk fibroin and sericin contents in SL had no significant difference compared with SY and 6 A raw silk. The silk protein antibody was used to verify the content of sericin and fibroin in the three kinds of raw silk by Western blot. It was found that the signal intensity of fibroin Fib-L and P25, and sericin Ser1 and Ser3 were basically the same among the three kinds of raw silk, but a strong Ser2 signal was detected in SL. Since Ser2 is non-cocoon silk protein, it is speculated that it does not influence on the performance of silk. In summary, the protein content of raw silk from Guican 5 reared on artificial diet in all instars was not significantly different from that of mulberry leaf and 6 A raw silk, which has the potential to replace the raw silk from mulberry leaf rearing cocoons for the development and application of high-quality silk products in the future.