Abstract
We purified a lectin from a pupal extract of Drosophila melanogaster. This lectin agglutinated trypsinized and glutaraldehyde-fixed bovine red blood cells in the presence of calcium or magnesium. The hapten sugar of this lectin was galactose. The molecular mass of the intact lectin was determined to be 41 kDa, and it comprised 14- and 17-kDa subunits. The 17-kDa subunit was shown to be a glycosylated form of the 14-kDa subunit. Analysis of the cDNA for this lectin revealed that the 14-kDa subunit consists of 163 amino acid residues and contains all residues conserved in various C-type lectins. It was suggested that the Drosophila lectin and Sarcophaga lectin share some properties and function similarly in defense and development, but probably they are not structural homologues.
Highlights
We have been studying the humoral lectin of Sarcophaga peregrina, focusing mainly on its biological function (18 –20)
Detection of Drosophila Lectin in the Pupal Extract—Sarcophaga lectin is known to be synthesized by the fat body at the pupal stage and to be secreted into the hemolymph [20], so a pupal extract of Drosophila was thought to be an appropriate
MgCl2 was effective, but its effect was a little weaker than that of CaCl2 (Table II). These results suggested that the hemagglutinating activity in the pupal extract of Drosophila is due to a galactose-binding C-type lectin like the Sarcophaga lectin
Summary
We have been studying the humoral lectin of Sarcophaga peregrina (flesh fly), focusing mainly on its biological function (18 –20). It was suggested that Sarcophaga lectin is essential for the differentiation of imaginal discs at the pupal stage [22]. It is becoming more and more clear that this lectin participates in both the defense and development (ontogeny) of this insect, which indicates that a single lectin can play two independent biological roles [23, 24]. From the similarity of the expression of the genes for the Drosophila and Sarcophaga lectins, we propose the functional similarity of these two lectins Their molecular masses are different, and their amino acid sequence identity is at most 25%
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call