Royal jelly proteome comparison between A. mellifera ligustica and A. cerana cerana

In this study, we compared royal jelly (RJ) produced by Apis mellifera ligustica and Apis cerana cerana in production, protein profiles, and abundances using proteomic approaches. The RJ proteome was displayed using two-dimensional gel electrophoresis (2DGE), and proteins were identified using MALDI-TOF MS and LC-Chip/ESI-QTOF MS. Differences in the RJ proteome between the two bee species were validated using western-blot analysis. RJ production by A. cerana cerana (3.21 +/- 0.43 g) is significantly lower than that of A. mellifera ligustica (80.5 +/- 7.83 g). The 2DGE based MS approach identified 52 and 60 proteins in the RJ of A. mellifera ligustica and A. cerana cerana, respectively. The majority of the identified proteins were major royal jelly proteins (MRJPs). Peroxiredoxin 2540, glutathione S-transferase S1, and MRJP5 were detected only in the RJ of A. mellifera ligustica, and MRJP1 was the most abundant MRJP. In contrast, MRJP7 was found only in the RJ of A. cerana cerana. But, similar to A. mellifera ligustica, MRJP1 was found most abundantly in this case too. In this study, glucose oxidase was identified for the first time in the A. cerana cerana RJ. Comparing the protein levels of MRJP1, 2, 3, 4, and 5 between the two species, they were significantly higher in the RJ of A. mellifera ligustica than in A. cerana cerana. This observation was supported by Western blot analysis using anti-MRJP1, 2, 3 antibodies. The result suggested that A. mellifera ligustica needs more nutrition to nurse the developing larvae and queens as compared to that of A. cerana cerana. This study improved our understanding of protein composition of RJ from Western and Eastern honeybees. RJ produced by A. mellifera ligustica exceeds the RJ from A. cerana cerana both in terms of production and health purposes.