More Drosophila enteroendocrine peptides: Orcokinin B and the CCHamides 1 and 2
Cell Tissue Res. 2014-05-22; 357(3): 607-621
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Veenstra JA(1), Ida T.
(1)INCIA UMR 5287 CNRS, Université de Bordeaux, Avenue des Facultés, 33405,
Talence Cedex, France, .
Antisera to orcokinin B, CCHamide 1, and CCHamide 2 recognize enteroendocrine
cells in the midgut of the fruitfly Drosophila melanogaster and its larvae.
Although the antisera to CCHamide 1 and 2 are mutually cross-reactive, polyclonal
mouse antisera raised to the C-terminals of their respective precursors allowed
the identification of the two different peptides. In both larva and adult,
CCHamide 2 immunoreactive endocrine cells are large and abundant in the anterior
midgut and are also present in the anterior part of the posterior midgut. The
CCHamide 2 immunoreactive endocrine cells in the posterior midgut are also
immunoreactive with antiserum to allatostatin C. CCHamide 1 immunoreactivity is
localized in endocrine cells in different regions of the midgut; those in the
caudal part of the posterior midgut are identical with the allatostatin A cells.
In the larva, CCHamide 1 enteroendocrine cells are also present in the endocrine
junction and in the anterior part of the posterior midgut. Like in other insect
species, the Drosophila orcokinin gene produces two different transcripts, A and
B. Antiserum to the predicted biologically active peptide from the B-transcript
recognizes enteroendocrine cells in both larva and adult. These are the same
cells as those expressing β-galactosidase in transgenic flies in which the
promoter of the orcokinin gene drives expression of this enzyme. In the larva, a
variable number of orcokinin-expressing enteroendocrine cells are found at the
end of the middle midgut, while in the adult, those cells are most abundant in
the middle midgut, while smaller numbers are present in the anterior midgut. In
both larva and adult, these cells also express allatostatin C. We also made a
specific polyclonal antiserum to the NPF precursor in order to determine more
precisely the expression of this peptide in the midgut. Using this antiserum, we
find expression in the midgut to be the same as described previously using
transgenic flies, while in the adult, midgut expression appears to be
concentrated in the middle midgut, thus suggesting that in the anterior midgut
only minor quantities of NPF are produced.