Honeybee (Apis mellifera ligustica) drone embryo proteomes

Little attention has been paid to the drone honeybee (Apis mellifera ligustica) which is a haploid individual carrying only the set of alleles that it inherits from its mother. Molecular mechanisms underlying drone embryogenesis are poorly understood. This study evaluated protein expression profiles of drone embryogenesis at embryonic ages of 24, 48 and 72 h. More than 100 reproducible proteins were analyzed by mass spectrometry on 2D electrophoresis gels. Sixty-two proteins were significantly changed at the selected three experimental age points. Expression of the metabolic energy requirement-related protein peaked at the embryonic age of 48 h, whereas development and metabolizing amino acid-related proteins expressed optimally at 72 h. Cytoskeleton, protein folding and antioxidant-related proteins were highly expressed at 48 and 72 h. Protein networks of the identified proteins were constructed and protein expressions were validated at the transcription level. This first proteomic study of drone embryogenesis in the honeybee may provide geneticists an exact timetable and candidate protein outline for further manipulations of drone stem cells.

Research highlights▶ Our data provided a first preliminary proteome map of honeybee drone embryos. ▶ More than 100 proteins were successfully identified and 62 of them altered expressions at embryonic ages of 24, 48 and 72 h. ▶ A significant number of proteins were up-regulated at age 48 h, a peak time at which carbohydrate and energy metabolism-related proteins are required the most. ▶ Protein involving in the cytoskeleton, antioxidants and protein folding were highly expressed at 48 and 72 h to maintain cell shape, or remove ROS or facilitate protein folding for the developing embryos. ▶ The biological interaction network and q-PCR validation results provide valuable information for geneticists to specify a precise embryonic age at which to select a suitable protein target for future manipulation of honeybee male stem cells for better pollination services or increased bee product yield.