title: Demonstration of the proopiomelanocortin signaling system in the primary immune organ of the quail.
abstract: There is growing evidence to suggest that proopiomelanocortin (POMC), a precursor of adrenocorticotropin and alpha-melanocyte-stimulating hormone (alpha-MSH), also exists in extrapituitary organs, including immune organs. We investigated the presence of the POMC signaling system in the avian-specific primary immune organ the bursa of Fabricius (BF) of the adult quail. Immunohistochemical staining revealed the presence of cells showing immunopositive reaction with anti-alpha-MSH antibody in the quail specimens. RT-PCR analysis revealed the expression of POMC, prohormone convertases (PC1/3 and PC2), and three melanocortin receptor subtype (MC1R, MC4R, and MC5R) mRNAs in total RNA specimens of the BF. These findings demonstrate that in the quail BF, just as in the pituitary, immunopositive alpha-MSH substances may be produced via specific cleavages of POMC by the sequential actions of PC1/3 and PC2. The observation of MCR expression within the BF suggests that the alpha-MSH substances may exert paracrine actions within the BF.
authors.affiliation: Department of Regulation Biology, Faculty of Science, Saitama University, Saitama, Japan. tkoba@mail.saitama-u.ac.jp
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Aya
authors.initials: A
authors.lastname: Takaso
authors.forename: Shigeyasu
authors.initials: S
authors.lastname: Tanaka
authors.forename: Masafumi
authors.initials: M
authors.lastname: Amano
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Takahashi
authors.forename: Shawichi
authors.initials: S
authors.lastname: Iwamuro
authors.forename: Takeo
authors.initials: T
authors.lastname: Machida
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation / Q000235:genetics / Q000276:immunology; D007107:Immune System / Q000276:immunology*; D008297:Male; D009928:Organ Specificity; D011333:Pro-Opiomelanocortin / Q000235:genetics / Q000276:immunology*; D011784:Quail / Q000276:immunology*; D015398:Signal Transduction / Q000276:immunology*; D000521:alpha-MSH / Q000378:metabolism
chemical_list: D000521:alpha-MSH; D011333:Pro-Opiomelanocortin