IMMUNOLOCALIZATION OF TWO PUTATIVE PIGMENTOTROPINS AKH I AND -MSH-LIKE IMMUNOREACTIVITIES IN THE BRAIN OF ROUGH WOODLOUSE, PORCELLIO SCABER AND PILL BUGS ARMADILLIDIUM VULGARE (CRUSTACEA, ISOPODA).

Abstract

Antisera against putative pigmentotropic neuropeptides, Adipokinetic hormone I (AKH I) and α-Melanocyte stimulating hormone (α-MSH) reacted with small sets of neurons in the cephalic ganglia of the isopoda Porcellio scaber and Armadillidium vulgare. The distributions of immunoreactivities resembled in the two species. AKH I-like immunoreactivity (AKH I-ir) occurs in both species. In P scaber 5 cells occurred in the optic lobe (OL) (3 small near Lamina ganglionaris, LG and 2 large dorsally) while in A.vulgare only one small cell near LG. The accessory lobe (AL) and subesophageal mass (SM) have the same pattern in both species. There are 2 cells in AL and 6 cells in SM (in the cells of mandibular ganglion,CMD). α-MSH immunoreactivity (α-MSH-ir) were located in OL, and SM in both species and in AL of A.vulgare. In P. scaber two large perikarya were located dorsally, one small ventrally, while in A.vulgare 4 large dorsally, one small ventrally and strong reactivity in pseudo-frontal organ (PFO). In AL, 3 immunopositive cells were observed. In SM 6 cells (4 in CMD, 2 in the cells of maxillulary ganglion, CML) in P scaber and 8 cells (6 in CMD, 2 in CML) were observed in A. vulgare. These results suggest the possible existence of AKH-like and α-MSH-like peptides in isopoda. No differences were detected between males and females. The projections of immunoreactive fibers were traced to several brain regions, the somatogastric nervous system and the neurohaemal organs, which suggest multiple functions of these peptides.