title: Possible Involvement of Photoperiodic Regulation in Reproductive Endocrine System of Female Olive Flounder Paralichthys olivaceus.
abstract: This study investigated possible involvement of photoperiodic regulation in reproductive endocrine system of female olive flounder. To investigate the influence on brain-pituitary axis in endocrine system by regulating photoperiod, compared expression level of Kisspeptin and sbGnRH mRNA in brain and FSH-β, LH-β and GH mRNA in pituitary before and after spawning. Photoperiod was treated natural photoperiod and long photoperiod (15L:9D) conditions from Aug. 2013 to Jun. 2014. Continuous long photoperiod treatment from Aug. (post-spawning phase) was inhibited gonadal development of female olive flounder. In natural photoperiod group, the Kiss2 expression level a significant declined in Mar. (spawning period). And also, FSH-β, LH-β and GH mRNA expression levels were increasing at this period. However, in long photoperiod group, hypothalamic Kiss2, FSH-β, LH-β and GH mRNA expression levels did not show any significant fluctuation. These results suggest that expression of hypothalamic Kiss2, GtH and GH in the pituitary would change in response to photoperiod and their possible involvement of photoperiodic regulation in reproductive endocrine system of the BPG axis.
authors.affiliation: Genetics & Breeding Research Center, National Fisheries Research & Development Institute, Geoje 656-842, Korea.
authors.forename: Hyun Chul
authors.initials: HC
authors.lastname: Kim
authors.affiliation: Marine Science Institute, Jeju National University, Jeju 695-965, Korea.
authors.forename: Chi Hoon
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Marine Science Institute, Jeju National University, Jeju 695-965, Korea.
authors.forename: Sung Pyu
authors.initials: SP
authors.lastname: Hur
authors.affiliation: Marine Science Institute, Jeju National University, Jeju 695-965, Korea.
authors.forename: Byeong Hoon
authors.initials: BH
authors.lastname: Kim
authors.affiliation: Marine Science Institute, Jeju National University, Jeju 695-965, Korea.
authors.forename: Jun Young
authors.initials: JY
authors.lastname: Park
authors.affiliation: Marine Science Institute, Jeju National University, Jeju 695-965, Korea.
authors.forename: Young Don
authors.initials: YD
authors.lastname: Lee
keywords: FSH-β; GH; Kisspeptin; LH-β; Olive flounder; Photoperiodic regulation