title: Evidence for expression of relaxin hormone-receptor system in the boar testis.
abstract: Although the physiological role of relaxin (RLN) in males remains largely unknown, there is limited evidence that the testis might be a candidate source and target of RLN in boars, as RLN transcripts are detected in the boar testis and it contains RLN-binding sites. To determine whether the boar testis acts as a source and target tissue of RLN, we characterised the expression pattern and cellular localisation of both RLN and its own receptor LGR7 (RXFP1) in boar testes during postnatal development by molecular and immunological approaches. Testes were collected from Duroc boars, and partial cDNA sequences of the boar homologue of human RXFP1 were identified. RLN expression increased through puberty onwards, while RXFP1 expression changed little during development. RLN mRNA and protein expression were restricted to the Leydig cells, whereas both Leydig cells and seminiferous epithelial cells expressed RXFP1 mRNA and protein. Interestingly, RLN was expressed in the testis as an 18 kDa form (the expected size of proRLN), but not as the 6 kDa mature form, during development because of a lack of the enzyme required for proRLN processing. In contrast, RXFP1 was detected at all stages as specific bands of 75 and 91-95 kDa (likely non-glycosylated and glycosylated RXFP1 respectively). Thus, we provide evidence for expression of RLN-RXFP1 ligand-receptor system in the boar testis, suggesting that the testis act as a source and possible target tissue of RLN.
authors.affiliation: Laboratory of Animal Reproduction and Physiology, Faculty of Agriculture, Shizuoka University, 836 Ohya, Suruga, Shizuoka-City, Shizuoka 422-8529, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Kato
authors.lastname: Siqin
authors.forename: Itaru
authors.initials: I
authors.lastname: Minagawa
authors.forename: Takuya
authors.initials: T
authors.lastname: Aoshima
authors.forename: Dai
authors.initials: D
authors.lastname: Sagata
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Konishi
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Yogo
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Kawarasaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sasada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tomogane
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kohsaka
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005786:Gene Expression Regulation / Q000502:physiology*; D008297:Male; D008969:Molecular Sequence Data; D043562:Receptors, G-Protein-Coupled / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018000:Receptors, Peptide / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012065:Relaxin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D013552:Swine / Q000502:physiology*; D013737:Testis / Q000378:metabolism*
chemical_list: D043562:Receptors, G-Protein-Coupled; D018000:Receptors, Peptide; C033395:relaxin receptors; D012065:Relaxin