Holtzhausen, W.D. (Wendy Dianne)Nicolson, Sue W.2007-07-172007-07-172007-04Holtshausen, WD & Nicolson, SW 2007, ‘Beetle diuretic peptides: The response of mealworm (Tenebrio molitor) Malpighian tubules to synthetic peptides, and cross-reactivity studies with a dung beetle’, Journal of Insect Physiology, vol.53, issue 4, pp. 361-369.[http://www.sciencedirect.com/science/journal/00221910]0022-191010.1016/j.jinsphys.2006.12.010http://hdl.handle.net/2263/3050This paper reports the effects of different diuretic factors on the Malpighian tubules of beetles. Calcitonin (CT)-like peptides from silkmoth and mosquito increase fluid secretion in a dose-dependent manner in the tubules of Tenebrio molitor, but the cockroach CT-like peptide, Dippu-DH31, has no effect. Thapsigargin induces a small but significant increase in tubule secretion rates. The interactions between different factors in mealworm tubules were explored by testing CT-like peptides, thapsigargin and the mealworm CRF-related diuretic factor Tenmo-DH37 in various combinations, but no synergistic effects were observed. C-terminal fragments of the CRF-related diuretic peptides Locmi-DH46 and Dippu-DH46 fail to increase fluid secretion in mealworm tubules, unlike their corresponding whole peptides. Cross-reactivity of factors between beetle species was investigated using the scarabaeid Onthophagus gazella. Tenmo-DH37 increases fluid secretion in isolated tubules of O. gazella in a dose-dependent manner, revealing a high degree of cross-reactivity in this distantly related beetle species. However, homogenates of O. gazella brains inhibited fluid secretion in mealworm tubules.402117 bytesapplication/pdfenElsevierCRF-related peptidesCalcitonin-like peptidesFluid secretionColeopteraMalpighian vesselsBeetlesDiureticsPeptidesMeal wormsDung beetlesPostprint Article