Neuroendocrine cells in Drosophila melanogaster producing GPA2/GPB5, a hormone with homology to LH, FSH and TSH
General and Comparative Endocrinology. 2011-02-01; 170(3): 582-588
DOI: 10.1016/j.ygcen.2010.11.015
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Sellami A(1), Agricola HJ, Veenstra JA.
Author information:
(1)Université de Bordeaux, CNIC UMR 5228 CNRS, 33400 Talence, France.
Thyrostimulin is a dimer hormone formed from glycoprotein A2 (GPA2) and
glycoprotein B5 (GPB5) that activates the TSH receptor in vertebrates. A
Drosophila GPA2/GPB5 homolog has recently been characterized. Cells producing
this novel hormone were localized by in situ hybridization using both the GPA2
and GPB5 DNA sequences and by making transgenic flies in which the GPB5 promoter
drives the expression of gal4. Endocrine cells producing GPA2/GPB5 were found in
the abdominal neuromeres and are different from the endocrine cells producing
crustacean cardioactive peptide or those making leucokinin. They are also not
immunoreactive to antisera to the CRF- or calcitonin-like diuretic hormones.
Their axons leave the central nervous system through the segmental nerves and
project to the periphery were they likely release GPA2/GPB5 into the hemolymph.
As has been described for the leucokinin endocrine cells their axons run over the
surface of the abdominal musculature, however, the projection patterns of the
leucokinin and GPA2/GPB5 neuroendocrine cells are not identical. The chances of
adult eclosion of insects from which the GPA2/GPB5 cells have been genetically
ablated or have been made to express GPB5-RNAi are severely compromised,
demonstrating the physiological importance of the cells producing this hormone.
As the receptor for GPA2/GPB5 stimulates the production of cyclic AMP (cAMP) and
is highly expressed in the hindgut, where cAMP stimulates water reabsorption in
locusts, it is suggested that GPA2/GPB5 may be an insect anti-diuretic hormone.
Copyright © 2010 Elsevier Inc. All rights reserved.