S. Karacali et al., Adhesion of hemocytes to desialylated prothoracic glands of Galleria mellonella (Lepidoptera) in the larval stage, INVERTEBR R, 37(2), 2000, pp. 167-170
Earlier work showed the existence of sialic acid (SA) in the prothoracic gl
ands (PGs) of Galleria mellonella (Karacali et al., 1997). In this paper we
investigated the role of SA during the degeneration process of PGs. Neuram
inidase-digested larval PGs were incubated within the hemolymph collected f
rom same age larvae. Light and electron microscopic observations showed inc
omplete capsule formation by the accumulation of hemocytes around desialyla
ted gland cells, but not in the control group. Desialylated larval PG cells
were recognized as a foreign structure or non-self by hemocytes. The resul
t indicates that SA acts as a mask for hemocytic receptors during the larva
l period under normal conditions. However, in the absence of SA, the glands
start to degenerate. We provide an explanation for the role of SA in the r
ecognition process of hemocytes that initiates the degeneration of PGs in p
upal cells and show the functionality of SA in insects, confirming that SA
is a universal molecule.