Polyacrylamide disc gel electrophoresis (PAGE) was performed on soluble proteins from the fat body, haemolymph (male and female), and ovary of the adult fresh water-bug, Laccotrephes rubra, in order to determine their protein patterns. The electrophoresis resulted in the separation of 16 and 17 protein components in male and female haemolymph respectively. In female fat body extracts 15 protein bands could be detected; whereas ovary extracts resolved into 11 protein bands only. Comparison of the electropherograms of protein pattern of fat body (FBPP), haemolymph (HPP) and ovary (OPP) revealed that the extra band present in the female haemolymph is common to both female fat body and ovary, which is suggestive of it being the female specific protein, i.e. vitellogenin. A careful examination of the various electropherograms further revealed that the majority of the protein bands of haemolymph and ovary are common to its corresponding fat body protein bands. This might suggest that the ovary derives most of its protein components from the surrounding haemolymph, which have presumably been synthesized and secreted by the fat body.

The histochemical analyses demonstrated that the female-specific protein band is a glycolipoprotein; and most of the haemolymph protein zones stain as glycoprotein, lipoprotein or ribonucleoprotein. ‘Stains-all’ technique however, revealed the presence of four possible RNA bands in fat body extracts.