Abstract: 【Aim】 To explore the molecular regulation mechanism of grafted larvae on ovarian development of queens in the Western honey bee, Apis mellifera. 【Methods】 The isobaric tags for relative and absolute quantitation (iTRAQ) method was used to quantify the proteins in the ovaries of queens reared from the larvae grafted at different instars and screen the differentially expressed proteins (DEPs). The results were validated by Western blotting. 【Results】 A total of 452 966 spectra were obtained and 3 642 proteins were identified from ovaries of A. mellifera queens. Gene Ontology (GO) analysis revealed that the DEPs in the ovaries of queens reared from the larvae grafted at different instars are associated with cell metabolism, cell division, and protein biosynthesis. The DEPs in the ovaries of queens reared from the larvae grafted between the 1st and 2nd instars are enriched in such pathways as carbohydrate metabolism, lipid metabolism, and exogenous degradation, while those reared from the larvae grafted between the 1st and 3rd instars mainly enriched in developmental pathways, ribosome pathways, and lysosome metabolism. The Western blotting results of the two differentially expressed storage proteins hexamerin 110 and hexamerin 70b showed that their expression levels decreased with the grafted larval instar. 【Conclusion】 The identification of differentially expressed proteins in the ovaries of A. mellifera queens reared from the larvae grafted at different instars provides a foundation for the regulatory mechanism of queen reproductive development and caste differentiation.  

Key words: Apis mellifera; grafted larva, instar, ovary, queen, proteomics, differentially expressed proteins