Search

In this study, we analyzed Apis mellifera royal jelly proteome alterations induced by supplementation with different concentrations of dietary organic zinc (0, 25, 50, and 75 ppm). Proteins extracted from royal jelly were separated by electrophoresis and isoelectric focusing, and zinc-containing protein spots were identified by tandem mass spectrometry. Organic zinc-containing diets modified total royal jelly protein content and altered the expression of five major royal jelly proteins (MRJP1, MRJP2, MRJP3, MRJP5, and MRJP8). While the diet with the lowest tested zinc content (Zn25) increased total royal jelly protein content and expression of MRJP1, diets with higher zinc contents (Zn50 and Zn75) decreased MRJP expression. Our results demonstrate that important proteins and metabolic processes are modified in royal jelly produced by honey bees supplemented with different concentrations of organic zinc source, affecting nutrition and maintenance of colonies. [ABSTRACT FROM AUTHOR]

This study assessed the effects of different protein levels on the development of the mandibular gland (MG) in six-day-old worker bees (Apis mellifera) during the dearth period. Twenty colonies were randomly assigned to one of four experimental diets containing 0%, 23%, 25%, or 27% crude protein (CP), with five replicates each. The experimental diets were composed of feed meal and honey sirup. Each colony was provided with 30 g of formulated feed every 3 days over a 36-day period. At the end of the experimental period, ten six-day-old worker bees were collected from each treatment for the morphological analysis of their MGs. The area of the MG was significantly larger in the bees fed protein-enriched feeds than in the controls. The height of the secretory cells in the MG was also significantly greater in all colonies fed protein-enriched feed than in the control group. However, the group that received the feed with 23% CP had significantly taller secretory cells than the other groups. Based on regression analysis, the ideal level of protein in the diet for the development of the MG was 22.2% CP. Thus, the use of protein-enriched feed promotes greater increases in the area and height of secretory MG cells in six-day-old honey bee workers. [ABSTRACT FROM AUTHOR]