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

MOLINÉ, MARÍA DE LA PAZ; VÁZQUEZ, M. MAGDALENA; MORAN GIARDINI, PALOMA; DOMÍNGUEZ, ENZO; FERNÁNDEZ, NATALIA J.; DAMIANI, NATALIA; QUINTANA, SILVINA; GENDE, LIESEL B.

JOURNAL OF APPLIED ENTOMOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2024 vol. 00 p. 1 - 9

0931-2048

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 antimicrobialpeptides like defensin. Inadequate nutrition also disrupts the redox balance onA. mellifera individuals, with superoxide dismutase and catalase being the key componentsof their antioxidant system. Vitellogenin is associated with the mobilizationof nutrients in early A. mellifera bee stages. Considering that Saccharomyces cerevisiaeis the second most significant by-productof 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 antioxidant-relatedgenes. To assess gene expression, we conducted RT-qPCR,using RNA extractedfrom 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-relatedgene 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.