Workers aged 2 and 100 days had no positive reactions for the anti-vitellogenin antibody (Fig. 4). Neither the 120 kDa protein found in workers aged 2 and 5 days nor the protein of 135 kDa from samples of workers aged 20–100 days reacted positively to the vg2 antibody (Fig. 4). The native vitellins from queens and workers were compared and their eggs showed one main protein with the same size (Fig. 5). In the haemolymph from 30 days old workers a similar protein was also identified (Fig.

5). In eggs from queens of ant species in the families Myrmicinae, Ponerinae and Ectatomminae the vitellin is formed by two or more proteins (Lewis et al., 2001 and Wheeler et al., 1999). Our results show that the eggs of E. tuberculatum queens have vitellins that consist of four major proteins, Depsipeptide order while in the eggs of workers only two of them are the vitellins. In queens, these four proteins join

to form an oligomeric protein which PD0332991 chemical structure in its native form has a molecular weight between 400 and 500 kDa estimated based on data from Wheeler et al. (1999). In the eggs of workers, the 156 and 31 kDa vitellins form an oligomeric protein with the same molecular weight of the native vitellin found in queens. The two proteins found in the greatest amounts in the egg extracts of E. tuberculatum were used for antibody production because the vitellins make up the largest fraction of proteins found in the eggs of insects ( Raikhel and Dhadialla, 1992 and Tufail and Takeda, 2008). The immunolocalization tests showed that these proteins occur in fat body cells, the main production site of vitellogenins. Since vitellogenins are the precursors of vitellins ( Chapman, 1998), our results confirm that these two proteins are actually vitellin compounds. Comparing the vitellins of the queen and worker eggs with the vitellogenins from their haemolymph revealed that only the proteins of 31 and 156 kDa were shared, suggesting

that the vitellogenin circulating in the haemolymph of E. tuberculatum consists GBA3 of only these two proteins. Also, the presence of a native protein in worker’s haemolymph with similar size of the native vitellins found in queen and worker eggs indicates that the vitellogenin forms a protein complex in the haemolymph similar to the vitellins found in the eggs. The proteins of 36 and 123 kDa present in the eggs of queens may be products of additional cleavage of the 156 kDa protein, which is supported by the occurrence of cross-reactivity between antibodies vg1 and vg2 to the proteins of 123 and 156 kDa. Moreover, the haemolymph of the queens shows only the proteins of 31 and 156 kDa. In B. germanica, vitellogenins of 160 kDa are cleaved into subunits of 50 and 95 kDa after internalization in the oocyte ( Wojchowski et al., 1986). The difference in vitellin processing found between queen and worker eggs of E.