Identification of cells expressing Calcitonins A and B, PDF and ACP in Locusta migratoria using cross-reacting antisera and in situ hybridization

• Published in: Peptides (New York, N.Y. : 1980) Vol. 146; p. 170667
• Main Author: Veenstra, Jan A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2021
• Subjects: ACP; Affinity column; Amino Acid Sequence; Animals; Calcitonin - chemistry; Calcitonin - immunology; Calcitonin - metabolism; Calcitonin A; Calcitonin B; Guinea Pigs; Immune Sera; In Situ Hybridization; Insect Proteins - chemistry; Insect Proteins - metabolism; Locust; Locusta migratoria - metabolism; Neuropeptides - chemistry; Neuropeptides - metabolism; PDF; PDF; Calcitonin A; Locust; Calcitonin B; ACP; Affinity column
• ISSN: 0196-9781; 1873-5169
• DOI: 10.1016/j.peptides.2021.170667

•Identification of calcitonin A producing neuroendocrine cells in locusts.•Identification of PDF-immunoreactive peptide in abdominal ganglia in locusts.•Identification of calcitonin B producing enteroendocrine cells in locusts. This work was initiated because an old publication suggested that electrocoagulation of four paraldehyde fuchsin positive cells in the brain of Locusta migratoria might produce a diuretic hormone, the identity of which remains unknown, since none of the antisera to the various putative Locusta diuretic hormones recognizes these cells. The paraldehyde fuchsin positive staining suggests a peptide with a disulfide bridge and the recently identified Locusta calcitonins have both a disulfide bridge and are structurally similar to calcitonin-like diuretic hormone. In situ hybridization and antisera raised to calcitonin-A and -B were used to show where these peptides are expressed in Locusta. Calcitonin-A is produced by neurons and neuroendocrine cells that were previously shown to be immunoreactive to an antiserum to pigment dispersing factor (PDF). The apparent PDF-immunoreactivity in these neurons and neuroendocrine cells is due to crossreactivity with the calcitonin-A precursor. As confirmed by both an PDF-precursor specific antiserum and in situ hybridisation, those calcitonin-A expressing cells do not express PDF. Calcitonin B is expressed by numerous enteroendocrine cells in the midgut as well as the midgut caeca. A guinea pig antiserum to calcitonin A seemed quite specific as it recognized only the calcitonin A expressing cells. However, rabbit antisera to calcitonin-A and-B both crossreacted with neuroendocrine cells in the brain that produce ACP (AKH/corazonin-related peptide), this is almost certainly due to the common C-terminal dipeptide SPamide that is shared between Locusta calcitonin-A, calcitonin-B and ACP.