Comparative Analysis Of The Proteome Of The Worker Eggs Of The Higher Royal Jelly Producing Bees (Apis Mellifera L.) And Italian Bees (Apis Mellifera L.)

Honeybee (Apis mellifera), as one of the model organisms studying developmental biology, aging, social behavior, neurobiology and so on, has successfully kept many eyes on it. Since the higher production royal jelly bee (Apis mellifera L.) was bred from the unselected native Italian bee (Apis mellifera L.) in the 1980s in China, it has become the best royal jelly producer in the world. Also, it is the rare genic resource for China and even for the world and gains more and more attention so far.The present study is pioneer employed two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MOLDI-TOF MS) to compare the proteome complement of the higher producing royal jelly bee (Apis mellifera L.) with the unselected native Italian bee (Apis mellifera L.) during 3 days egg development of the worker bees. This study could lay a foundation in further understanding the developmental feature and the potential molecular mechanism of high royal jelly producing behavior.The results showed that the detected spot number on day 1, day 2 and day 3 of the higher production royal jelly worker bee (Apis mellifera L.) were 502, 523 and 516, respectively. Whereas, the detected spot number on day 1, day 2 and day 3 of the unselected native Italian bee (Apis mellifera L.) were 349, 361, 354, respectively, indicating significant higher numbers of gene are expressed in the royal jelly producing bee (Apis mellifera L.) than those of the unselected native Italian bee (Apis mellifera L.) during their embrogenesis.The results also showed that the consistently expressed protein with no significant expressional volume change was about 45 percent in the higher production royal jelly worker bee (Apis mellifera L.) and the unselected native Italian worker bee (Apis mellifera L.) correspondingly. While the rest of them were of the great change in the expressional volume, suggesting they may be necessary and collaboratively regulate to the worker egg's development in terms of the expressional volume change.By comparison of the well resolved proteins between the higher production royal jelly worker bee (Apis mellifera L.) and the unselected native Italian worker bee (Apis mellifera L.) along with the egg development, most of them have high abundance and similar expressional trend, indicating these proteins are indispensable for the worker bee egg development, and regulating the developmental process by similar expressional pattern. However, 7 of them were of different expressional trend, indicating the genes involving in these proteins expression may be related to the royal jelly yield.Along with the worker bee egg development, the numbers of the protein spots with the highest expressional volume displayed the significant up trend in the higher production royal jelly Along with the worker bee egg development, the numbers of the protein spots with the highest expressional volume displayed the significant up trend in the higher production royal jelly worker bee (Apis mellifera L.), whereas, it didn't show significant change trend in the unselected native Italian worker bee (Apis mellifera L.). In addition, more genes take part in regulating the protein expression on day 3 in the higher production royal jelly worker bee (Apis mellifera L.), however, the number of silenced genes was no significant change in the unselected native Italian worker bee (Apis mellifera L.). The results suggest that the genes express more active in the higher production royal jelly worker bee (Apis mellifera L.) than that in the unselected native Italian worker bee (Apis mellifera L.) along with egg development, which may be relate to the royal jelly yield.Meanwhile, by comparison of the proteins mutual-matched on day 1, day 2 and day 3 in two species respectively, there were over 70% proteins with similar expressional trend during the 3 days' eggs development accordingly, suggesting these proteins are indispensable for the eggs development each day.Furthermore, more than 90 percent proteins specific to the two strains expressed in low abundance during the egg development, indicating the proteins expressed from these genes with polygenetic effects on the royal jelly production, which is in agreement with the royal jelly production is a genetic dominated quantities trait controlled by the cumulative effects of many genetic loci.38 proteins with high abundance that always expressed during the embryogenesis in the two species were analyzed by MALDI-TOF and the protein engine identification tool. Among them, 23 proteins were identified, and 15 did not be matched perfectly. According to functional classification of the identified proteins, 6 proteins were related to the metabolism of carbohydrates and energy, 6 proteins belonged to heat shock protein family, 3 proteins were related to cytoskeleton proteins, 4 proteins were related to antioxidant system and 4 proteins were related to cell circle. Of the identified, 21 proteins belonged to honeybee genome, 1 newly found protein relating to cytoskeleton was from the genome of Strongylocentrotus purpuratus, and another 1 newly found protein relating to cell circle was form Drosophila pseudoobscura.