Various insects that utilize vitamin-deficient diets derive a supplementary supply of these micronutrients from their symbiotic microorganisms. Here, we tested the inference from genome annotation that the symbiotic bacterium Buchnera aphidicola in the pea aphid Acyrthosiphon pisum provides the insect with vitamins B₂ and B₅ but no other B-vitamins. Contrary to expectation, aphid survival over five days of larval development on artificial diets individually lacking each B-vitamin not synthesized by Buchnera was not significantly reduced, despite significantly lower carcass B₁, B₃, B₆ and B₇ concentrations in the aphids on diets lacking each of these B-vitamins than on the vitamin-complete diet. Aphid survival was, however, significantly reduced on diet containing low concentrations (≤0.2 mM) or no pantothenate (B₅). Complementary transcriptome analysis revealed low abundance of the sense-transcript, but high abundance of the antisense transcript, of the Buchnera gene panC encoding the enzyme mediating the terminal reaction in pantothenate synthesis. We hypothesize that metabolic constraints or antisense transcripts may reduce Buchnera-mediated production of pantothenate, resulting in poor aphid performance on pantothenate-free diets. The discrepancy between predictions from genome data and empirical data illustrates the need for physiological study to test functional inferences made from genome annotations.

利用缺乏维生素的饮食的各种昆虫都从它们的共生微生物中补充了这些微量营养素。在这里，我们测试了从基因组注释中得出的推论，即豌豆蚜虫Acyrthosiphon pisum中的共生细菌Buchnera aphidicola为昆虫提供了维生素B ₂和B _5，但没有其他B-维生素。与预期相反，尽管car体B ₁，B ₃，B ₆和B ₇明显降低，但在单独缺乏由Buchnera合成的各种B族维生素的人工饮食下，幼虫发育5天后的蚜虫存活率并未显着降低。与不含维生素B的饮食相比，缺乏这些B-维生素的饮食中的蚜虫中维生素C的含量较高。然而，在低浓度（≤0.2mM）或不含泛酸（B ₅）的饮食中，蚜虫的存活率显着降低。互补转录组分析显示，Buchnera基因panC编码泛酸合成中终端反应的酶，其有义转录物的丰度低，而反义转录物的丰度高。我们假设代谢限制或反义转录本可能会减少布氏杆菌介导的泛酸生产，导致在无泛酸饮食中蚜虫的表现较差。来自基因组数据的预测与经验数据之间的差异说明，需要进行生理研究以测试由基因组注释做出的功能性推论。