Fig 1.
Scanning Electron Micrographs (SEM) from dorsal side of antennae of M. scutellaris worker.
(A) View of the head and dorsal surface of the antennae; pedicel (P), scape (S) and flagellum (F). (B) Distal view of flagellomere 8 highlighting sensilla trichodea a (Tr-a) and b (Tr-b). (C) Snapshot of flagellomere 9, flanked by flagellomeres 8 and 10 on the right and left sides, respectively; zoomed area of flagellomere 9 highlighting the sensillum coeloconica (co). (D) Higher magnification of flagellomere 9 highlighting the sensilla campaniformia (ca) and ampullaceal (am). (E) Flagellomere 10 and distal limit of flagellomere 9 showing a large number of sensilla basiconica, some of them are indicated by arrows. (F) High magnification of flagellomere 10 showing sensilla basiconica (Ba), placodea (pl) and campaniformia (ca).
Fig 2.
SEM from the dorsal side of the antenna of M. scutellaris queen.
(A) View of pedicel (P) and scape (S). Snapshots from (B) flagellomere 2 and (C) flagellomere 4. (D) Medial segment of flagellomere 5 highlighting showing sensilla trichodea a (Tr-a), trichodea b (Tr-b), sensilla basiconica (Ba), placodea (pl), campaniformia (ca) and ampullaceal (am). (E) Higher magnification of sensilla trichodea a (Tr-a) and trichodea b (Tr-b) from D. (F) Distal region of flagellomere 8 showing sensilla coeloconica (co), campaniformia (ca) and ampullaceal (am).
Fig 3.
SEM from dorsal side of antenna of M. scutellaris male.
(A) View of head, scape (S), pedicel (P), and 11 antennal flagellomeres (F); the eleventh flagellomere is indicated (arrow). (B) Distal region of flagellomere 8 and proximal region of flagellomere 9. (C) Distal region of flagellomere 10 showing sensilla trichodea a (Tr-a), trichodea b (Tr-b), sensilla placodea (pl), sensilla ampullaceal (am), and sensilla coeloconica (co). (D) Higher magnification of C to highlight sensilla coeloconica (co). (E) Higher magnification of C to emphasize sensilla placodea (pl) and sensilla ampullaceal (am).
Table 1.
Distribution pattern of sensilla in Melipona scutellaris antennae.
Table 2.
Number of sensilla on the dorsal side of Melipona scutellaris antenna.
Fig 4.
SEM from Pre-Defecating Larva (PDL) of M. scutellaris.
(A) Panoramic view of the anterior region, including part of the larvae body. (B) Frontal view of the head showing ocular lobe (ol), antennal lobe (al), clypeus (co), and mandible (ma). (C) Clypeus area showing sensilla-like structures, which are highlighted in (D)—arrows indicate small “black dots” that are orifices at the base of the structure. (E) View of antennal lobe region with four structures similar to immature sensilla, two of which were highlighted (F) in higher magnification. (G) Mandible region also showing structures similar to immature sensilla, which are emphasized in higher magnification in (H) with small orifices indicated by arrows.
Fig 5.
ELISA for MscuOBP8 detection in immature stages of Melipona scutellaris.
The native MscuOBP8 protein was detected, using an ELISA assay with a monoclonal antibody scFv anti-MscuOBP8 selected from a phage display library. The test was conducted in the larval stages (instars): L2 – 2nd stage larvae; L3 – 3rd stage (sub-stages: L3-1, L3-2 and L3-3); PDL stage (pre-defecating) and DL stage (defecating larvae); Positive control: recombinant MscuOBP8 as positive control; Negative control: carbonate/bicarbonate buffer (no protein sample).
Fig 6.
MscuOBP8 detection and localization in Melipona scutellaris PDL larvae by immunohistochemistry using a monoclonal scFv antibody.
A–SEM of Melipona scutellaris larvae head. B–Immunohistochemistry of Melipona scutellaris larvae (head circled), negative control (haematoxylin & eosin staining– 4X). C—Zoomed mandibular region spotted in A. D–MscuOBP8 was detected by specific staining of larvae tegument in the mandibular region (40X), comparatively to C. SEM—scanning electron microscopy; MscuOBP8 –Melipona scutellaris Odorant Binding Protein.
Fig 7.
Predicted tri-dimensional (3D) structure of MscuOBP8 with a putative binding pocket.
The protein structure is displayed in a rainbow pattern with the N-terminus in blue. JH III was docked into the putative binding pocket, which is covered by a C-terminal tail. JH surface is showing with a 50% transparent mesh to highlight the putative binding cavity.