INRA, UMR 406 Abeilles et Environnement, Domaine Saint-Paul, 84914 Avignon, France.
BMC Genomics. 2011 Oct 10;12:496. doi: 10.1186/1471-2164-12-496.
Malnutrition is a major factor affecting animal health, resistance to disease and survival. In honey bees (Apis mellifera), pollen, which is the main dietary source of proteins, amino acids and lipids, is essential to adult bee physiological development while reducing their susceptibility to parasites and pathogens. However, the molecular mechanisms underlying pollen's nutritive impact on honey bee health remained to be determined. For that purpose, we investigated the influence of pollen nutrients on the transcriptome of worker bees parasitized by the mite Varroa destructor, known for suppressing immunity and decreasing lifespan. The 4 experimental groups (control bees without a pollen diet, control bees fed with pollen, varroa-parasitized bees without a pollen diet and varroa-parasitized bees fed with pollen) were analyzed by performing a digital gene expression (DGE) analysis on bee abdomens.
Around 36, 000 unique tags were generated per DGE-tag library, which matched about 8, 000 genes (60% of the genes in the honey bee genome). Comparing the transcriptome of bees fed with pollen and sugar and bees restricted to a sugar diet, we found that pollen activates nutrient-sensing and metabolic pathways. In addition, those nutrients had a positive influence on genes affecting longevity and the production of some antimicrobial peptides. However, varroa parasitism caused the development of viral populations and a decrease in metabolism, specifically by inhibiting protein metabolism essential to bee health. This harmful effect was not reversed by pollen intake.
The DGE-tag profiling methods used in this study proved to be a powerful means for analyzing transcriptome variation related to nutrient intake in honey bees. Ultimately, with such an approach, applying genomics tools to nutrition research, nutrigenomics promises to offer a better understanding of how nutrition influences body homeostasis and may help reduce the susceptibility of bees to (less virulent) pathogens.
营养不良是影响动物健康、抵抗力和生存的主要因素。在蜜蜂（Apis mellifera）中，花粉是蛋白质、氨基酸和脂质的主要饮食来源，对于成年蜜蜂的生理发育至关重要，同时降低了它们对寄生虫和病原体的易感性。然而，花粉对蜜蜂健康的营养影响的分子机制仍有待确定。为此，我们研究了花粉营养对被螨虫 Varroa destructor 寄生的工蜂转录组的影响，这种螨虫已知会抑制免疫力并缩短寿命。通过对蜜蜂腹部进行数字基因表达（DGE）分析，我们对 4 个实验组（没有花粉饮食的对照蜂、有花粉饮食的对照蜂、没有花粉饮食的被螨虫寄生的蜂和有花粉饮食的被螨虫寄生的蜂）进行了分析。
每个 DGE 标签文库产生约 36000 个独特的标签，这些标签大约匹配 8000 个基因（蜜蜂基因组中基因的 60%）。将有花粉和糖饮食的蜜蜂与只限于糖饮食的蜜蜂的转录组进行比较，我们发现花粉激活了营养感应和代谢途径。此外，这些营养物质对影响长寿和某些抗菌肽产生的基因有积极影响。然而，螨虫寄生导致病毒种群的发展和代谢的下降，特别是通过抑制对蜜蜂健康至关重要的蛋白质代谢。花粉的摄入并没有逆转这种有害影响。
本研究中使用的 DGE 标签分析方法被证明是分析与蜜蜂营养摄入相关的转录组变化的有力手段。最终，通过这种方法，应用基因组学工具进行营养研究，营养基因组学有望更好地理解营养如何影响身体的内稳态，并可能有助于降低蜜蜂对（毒性较弱）病原体的易感性。
