Differential expression of aquaporin genes during ovary activation in the honeybee Apis mellifera (Hymenoptera: Apidae) queens.

Aquaporins are membrane proteins responsible for the rapid transport of water and solutes through the plasma membrane in almost all organisms including microorganisms, animals and plants. The knowledge about aquaporins in insects has advanced in the last years, especially in organs such as the gut and Malpighian tubules, but their roles in ovaries are poorly understood. This study reports the occurrence and the expression of gene profiles of predicted aquaporins in the ovaries of virgin and mated queens of the honeybee Apis mellifera. The expression of six aquaporin genes (Am-DRIP, Am-PRIP, Am-Eglp1, Am-Eglp2, Am-Eglp3 and Am-BIB) was investigated in the ovaries of queens of different ages and physiological status. The Am-Eglp3 has the higher level of transcript in newly emerged virgin queens. The Am-PRIP and Am-Eglp2 have a higher level of transcripts in 4 days-old virgin queens, aged expected to mate. In mated queens, only the Am-Eglp2 show high level of transcripts. Aquaporin was immunolocalized in the follicular cells of both nurse and oocytic chambers of the previtellogenic and vitellogenic follicles. This is the first report for the presence of aquaporins in the ovaries of bees.