Wu Xuehui, Chen Xuedong, Ye Aihong, Cao Jinru, He Ruimin, Pan Meiliang, Jin Feng, Ma Huanyan, Zhou Wenlin
Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China.
Shengzhou Mulsun Biotech Co., Ltd., Shengzhou, Zhejiang, China.
Front Mol Biosci. 2022 Aug 17;9:977047. doi: 10.3389/fmolb.2022.977047. eCollection 2022.
Use of formula feed (FF) for silkworms for all instars, has promoted transformation and progress in traditional sericulture. However, the cocoon yield of FF silkworms has failed to reach that of silkworms fed mulberry leaves (ML). The biological mechanisms underlying this phenomenon have not been well described. This study aimed to identify metabolic mechanisms and potential biomarkers relating to the poor cocoon yield of FF silkworms. In this study, silkworms received treatments of either ML (ML group) or FF (FF group) for all instars. At the 3rd day of the 5th instar, the midgut (MG), hemolymph (HL) and posterior silk gland (PSG) were collected for the metabolome profiles detection. The remaining silkworms were fed ML or FF until cocooning for investigation. The whole cocoon yield (WCY) was significantly higher in the FF group than the ML group ( < 0.05), whereas the cocoon shell weight (CSW) and cocoon shell rate (CSR) were significantly lower in the FF group ( < 0.05). A total of 845, 867 and 831 metabolites were qualified and quantified in the MG, HL and PSG of the FF silkworms, respectively. Correspondingly, 789, 833 and 730 metabolites were quantified in above three tissues of the ML group. Further, 230, 249 and 304 significantly different metabolites (SDMs) were identified in the MG, HL and PSG between the FF and ML group, respectively. Eleven metabolic pathways enriched by the SDMs were mutual among the three tissues. Among them, cysteine and methionine metabolism, arginine biosynthesis, and arginine and proline metabolism were the top three pathways with the highest impact value in the PSG. Six biomarkers were obtained through biomarker analysis and Pearson correlation calculation. Among them, homocitrulline, glycitein, valyl-threonine, propyl gallate and 3-amino-2,3-dihydrobenzoic acid were positively correlated with WCY, but negatively correlated with CSW and CSR ( < 0.05). An opposite correlation pattern was observed between 3-dimethylallyl-4-hydroxyphenylpyruvate and the three cocoon performance traits. Overall, three key metabolic pathways and six biomarkers associated with cocoon yield were interpreted, and should provide directions for formula feed optimization in factory-raised silkworms.
对各龄期家蚕使用配方饲料促进了传统养蚕业的转型与发展。然而，食用配方饲料的家蚕茧产量未能达到食用桑叶的家蚕的茧产量。这一现象背后的生物学机制尚未得到充分阐释。本研究旨在确定与食用配方饲料的家蚕茧产量低相关的代谢机制和潜在生物标志物。在本研究中，家蚕在各龄期均接受桑叶（桑叶组）或配方饲料（配方饲料组）处理。在五龄期第3天，采集家蚕的中肠、血淋巴和后部丝腺用于代谢组学分析。其余家蚕继续喂食桑叶或配方饲料直至结茧以进行观察。配方饲料组的全茧量显著高于桑叶组（<0.05），而配方饲料组的茧层量和茧层率显著低于桑叶组（<0.05）。在食用配方饲料的家蚕的中肠、血淋巴和后部丝腺中分别鉴定并定量了845、867和831种代谢物。相应地，在桑叶组的上述三个组织中定量了789、833和730种代谢物。此外，在配方饲料组和桑叶组的中肠、血淋巴和后部丝腺中分别鉴定出230、249和304种显著差异代谢物。在这三个组织中，有11条由显著差异代谢物富集的代谢途径是相同的。其中，半胱氨酸和甲硫氨酸代谢、精氨酸生物合成以及精氨酸和脯氨酸代谢是后部丝腺中影响值最高的前三条途径。通过生物标志物分析和Pearson相关性计算获得了6种生物标志物。其中，高瓜氨酸、黄豆黄素、缬氨酰 - 苏氨酸、没食子酸丙酯和3 - 氨基 - 2,3 - 二氢苯甲酸与全茧量呈正相关，但与茧层量和茧层率呈负相关（<0.05）。3 - 二甲基烯丙基 - 4 - 羟基苯丙酮酸与三个茧质性状呈现相反的相关模式。总体而言，阐释了与茧产量相关的三条关键代谢途径和六种生物标志物，应为工厂化饲养家蚕的配方饲料优化提供指导。
