Immune and antioxidant gene expression stimulation of Apis mellifera (Hymenoptera: Apidae) larvae by Saccharomyces cerevisiae from the brewering industry

M.P. MOLINE; VAZQUEZ, M.M; MORAN GIARDINI P; DOMINGUEZ, E.; FERNANDEZ N.J.; DAMIANI, N.; QUINTANA, S.; GENDE L.B

Journal of Applied Entomology

John Wiley and Sons Inc

Año: 2024 vol. 00 p. 1 - 9

The high overwinter mortalities in the honey bee population of Apis mellifera havebeen linked to immunocompromised individuals experiencing nutritional limitations.Larval nutrition plays a crucial role in determining the successful development ofadults, making them more susceptible to bacterial diseases when undernourished.One of the main intracellular signalling pathways in the larval immune system againstbacterial diseases is the Toll receptor signalling pathway, which activates antimicrobial peptides like defensin. Inadequate nutrition also disrupts the redox balance onA. mellifera individuals, with superoxide dismutase and catalase being the key components of their antioxidant system. Vitellogenin is associated with the mobilizationof nutrients in early A. mellifera bee stages. Considering that Saccharomyces cerevisiae is the second most significant by-product of the brewing industry, it may serveas a valuable raw material. We investigated the impact of feeding larvae with liveS. cerevisiae cells on the relative expression of their main immune and antioxidantrelated genes. To assess gene expression, we conducted RT-qPCR, using RNA extracted from ten larvae per treatment on the seventh day when the feeding trialconcluded. Importantly, the presence of S. cerevisiae did not affect larval survivalcompared to the control group. However, the relative expression of immune-relatedgene toll18W and antioxidant-related gene sod in larvae fed with live S. cerevisiae cellswas significantly higher than in larvae that were not fed with them. This suggeststhat the inclusion of S. cerevisiae in their diet may provide larvae with a nutritionaladvantage. Additionally, the vitellogenin (vg) gene expression increased in treatedlarvae compared to the control group, potentially facilitating their access to nutrientsand, consequently, enhancing their ability to cope with nutritional stress.