Michael J. StewartPraphaporn StewartMorakot SroyrayaNantawan SoonklangScott F. CumminsPeter J. HannaWei DuanPrasert SobhonDeakin UniversityUniversity of the Sunshine CoastFaculty of Medicine, Thammasat UniversityMahidol University2018-10-192018-10-192013-02-01Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology. Vol.164, No.2 (2013), 276-29015314332109564332-s2.0-84870312700https://repository.li.mahidol.ac.th/handle/123456789/31370The crustacean X-organ-sinus gland (XO-SG) complex controls molt-inhibiting hormone (MIH) production, although extra expression sites for MIH have been postulated. Therefore, to explore the expression of MIH and distinguish between the crustacean hyperglycemic hormone (CHH) superfamily, and MIH immunoreactive sites (ir) in the central nervous system (CNS), we cloned a CHH gene sequence for the crab Portunus pelagicus (Ppel-CHH), and compared it with crab CHH-type I and II peptides. Employing multiple sequence alignments and phylogenic analysis, the mature Ppel-CHH peptide exhibited residues common to both CHH-type I and II peptides, and a high degree of identity to the type-I group, but little homology between Ppel-CHH and Ppel-MIH (a type II peptide). This sequence identification then allowed for the use of MIH antisera to further confirm the identity and existence of a MIH-ir 9. kDa protein in all neural organs tested by Western blotting, and through immunohistochemistry, MIH-ir in the XO, optic nerve, neuronal cluster 17 of the supraesophageal ganglion, the ventral nerve cord, and cell cluster 22 of the thoracic ganglion. The presence of MIH protein within such a diversity of sites in the CNS, and external to the XO-SG, raises new questions concerning the established mode of MIH action. © 2012 Elsevier Inc.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyArticleSCOPUS10.1016/j.cbpa.2012.10.029