Morphophysiological Differences between the Metapleural Glands of Fungus-Growing and Non–Fungus-Growing Ants (Hymenoptera, Formicidae)
Figure 1
Schematic representation, histology, and histochemistry of the metapleural gland of the basal ant Ectatomma brunneum.
Secretory cells (sc) and their nuclei (n), extracytoplasmic portions of canaliculi (ec) and their nuclei (n), collecting chamber (cc), sieve plate (p) and reservoir (r) with opening (og), lined by epithelium (ep) and cuticular intima (cut) are shown. A–C: Histological sections of the metapleural gland stained with hematoxylin and eosin (staining in nucleus and cytoplasm). Details of secretory cells (sc) and their nuclei (n), intracytoplasmic (arrow) and extracytoplasmic portions of canaliculi (ec) with nuclei (n). Note canaliculi surrounding the nucleus of the secretory cell and arising individually from each cell and opening in the sieve plate (p) of the collecting chamber (cc) lined by the cuticular intima (cut), and the reservoir storing secretion (sec). Scale bar = 25 µm. D–E: Histological sections of the metapleural gland stained with PAS/methyl green (for detecting polysaccharides and RNA). Details of the secretory cells (sc) showing the cytoplasm, nucleus (n), intracytoplasmic (arrow) and extracytoplasmic (ec) canaliculi, collecting chamber (cc), and the lining epithelium (arrow) and nuclei of cells (arrow). Note the presence of secretion (sec) containing polysaccharides in the collecting chamber and reservoir. Scale bar = 25 µm. F: Histological sections of the metapleural gland stained with bromophenol blue (for detecting total proteins). Details of the secretory cells (sc), intracytoplasmic (arrow) and extracytoplasmic (ec) portions of canaliculi, and collecting chamber (cc) lined by epithelium (ep). Note the presence of secretion (sec) in the collecting chamber. Scale bar = 25 µm. G–H: Histological sections of the metapleural gland stained with Nile blue (for detecting acidic lipids). Details of the secretory cells (sc), intracytoplasmic (arrow) and extracytoplasmic (ec) portions of canaliculi, lining epithelium (arrow) of the collecting chamber (cc), and the reservoir (r). Note the presence of secretion (sec) containing acidic lipids in the reservoir. Scale bar = 25 µm.