A Genetic Strategy to Measure Circulating Drosophila Insulin Reveals Genes Regulating Insulin Production and Secretion (original) (raw)
Figure 2
Physiological regulation of Ilp2HF production and secretion.
(A) hemolymph trehalose concentrations in 1 and 3 day-old y1 w1118 control and Ilp21 gd2HF flies. (B) Ilp2 or Ilp2HF mRNA levels in 1 and 3 day-old y1 w1118 control and Ilp21 gd2HF flies. (C) Circulating Ilp2HF concentration in hemolymph was determined by sandwich ELISA using 41 pM (0.1 pg/µl) to 4150 pM (10 pg/µl) of FLAG(GS)HA, a peptide harboring FLAG and HA epitopes, but up to 830 pM are shown in the curve. (D) Measurement of the total Ilp2HF content in 1 and 3 day-old Ilp21 gd2HF flies. (E) Circulating Ilp2HF concentration (pM) or content per fly (pg) in 1 and 3 day-old Ilp21 gd2HF flies. (F) Secreted and remaining Ilp2HF content from isolated Ilp21 gd2HF heads that were incubated in 3 mM or 100 mM KCl. (G) Oral glucose-stimulated insulin secretion and clearance in 3 day-old Ilp21 gd2HF flies, measured by insulin ELISA. Circulating Ilp2HF was measured at 24 hours of fasting, or at 0, 30, 60, and 90 minutes after feeding with 2 M glucose for 30 minutes. In all figures, center values are averages, error bars represent the standard deviation, and two-tailed _t_-tests were used to generate p values. * indicates p<0.05, ** p<0.01, and *** p<0.001. N.S. indicates statistically not significant.