Common electrophoretic properties of the fat body, haemolymph, and oöcytes of adult Tenebrio molitor

Abstract

Electropherograms of the haemolymph indicated the presence, at a pH of 9·8, of eighteen negatively charged proteins of which at least five (bands Nos. 4, 13, 14, 15 and 16 from the origin) were common to the fat body and oöcytes. The distribution of the per cent composition of the five bands varied between unmated and mated females in the three tissues over the 4 days studied (days 3, 7, 8, and 10 after emergence). Circumstantial evidence suggested a three-step process of fat body protein synthesis followed by protein release into the haemolymph and its subsequent uptake by the oöcytes. Band No. 13 had the highest average per cent composition for both mated and unmated females in all three tissues reaching a maximum, on day 7 after emergence, of 56 (unmated females) or 58 (mated females) per cent of the total protein concentration in the oöcytes. Band No. 4, however, held the highest per cent composition of the five measured haemolymph protein bands on day 3 after emergence for both mated and unmated females, and on days 8 and 10 after emergence for unmated females when in the fat body it was also tied with band No. 13 for highest per cent composition. On day 3 after emergence fat body band No. 16, in mated females, represented the highest per cent composition of total protein and was four times higher than in unmated females of the same age, and similarly in the oöcytes, on day 3, band No. 16 was 34 per cent higher for mated than unmated females. Spectrophotometric analyses of fluctuations in the haemolymph protein concentration indicated a similar pattern for unmated and mated females from emergence to day 10 after emergence, the haemolymph protein concentration being significantly greater ( P<0·05) for mated females on days 4 and 9 after emergence (0·05> P>0·025). The mean value on day 9 was approximately 60 per cent higher for mated than unmated females. A possible relationship between the cyclic pattern of haemolymph protein concentration and the patterns of fat body protein and RNA synthesis is discussed.