title: KISS1 gene expression in the developing brain of female pigs in pre- and peripubertal periods.
abstract: Puberty is associated with an increase in gonadotropin secretion as a result of an increase in gonadotropin-releasing hormone (GnRH) secretion. Kisspeptin is considered to play a key role in puberty onset in many mammalian species, including rodents, ruminants and primates. The present study aimed to determine if changes in hypothalamic expression of the KISS1 gene, encoding kisspeptin, are associated with the onset of puberty in pigs. The animals (n=4 in each group) were perfused with 4% paraformaldehyde at 0, 1, 2, 3 and 4 months old, as prepubertal stages, and at 5 months old, as the peripubertal stage, following each blood sampling. KISS1 gene expressions in coronal sections of brains were visualized by in situ hybridization. Plasma luteinizing hormone (LH) was measured by radioimmunoassay. KISS1 mRNA signals were observed in the arcuate nucleus (ARC) at all ages examined without any significant difference in the number of KISS1-expressing cells, indicating that the KISS1 gene is constantly expressed in the ARC throughout pubertal development in pigs. The plasma LH concentration was the highest in 0-month-old piglets and significantly decreased in the 1- and 2 month-old groups (P<0.05), suggesting a developing negative feedback mechanism affecting gonadotropin release during the prepubertal period. Considering the potent stimulating effect of kisspeptin on gonadotropin release in prepubertal pigs, kisspeptin secretion rather than kisspeptin synthesis may be responsible for the onset of puberty in pigs.
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
authors.forename: Nahoko
authors.initials: N
authors.lastname: Ieda
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Uenoyama
authors.forename: Yoko
authors.initials: Y
authors.lastname: Tajima
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nakata
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kano
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Naniwa
authors.forename: Youki
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Shiori
authors.initials: S
authors.lastname: Minabe
authors.forename: Junko
authors.initials: J
authors.lastname: Tomikawa
authors.forename: Naoko
authors.initials: N
authors.lastname: Inoue
authors.forename: Fuko
authors.initials: F
authors.lastname: Matsuda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ohkura
authors.forename: Kei-Ichiro
authors.initials: K
authors.lastname: Maeda
authors.forename: Hiroko
authors.initials: H
authors.lastname: Tsukamura
mesh_terms: D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000254:growth & development / Q000378:metabolism*; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D059648:Kisspeptins / Q000235:genetics / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000097:blood; D010053:Ovary / Q000254:growth & development; D011374:Progesterone / Q000097:blood; D012741:Sexual Maturation; D013552:Swine
chemical_list: D059648:Kisspeptins; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone