title: Involvement of second messengers in the signaling pathway of vitellogenesis-inhibiting hormone and their effects on vitellogenin mRNA expression in the whiteleg shrimp, Litopenaeus vannamei.
abstract: We incubated fragments of Litopenaeus vannamei ovary to investigate second messengers involved in the regulation of vitellogenin (vg) mRNA levels. The use of 100nM recombinant vitellogenesis-inhibiting hormone (VIH) (corresponding to recombinant L. vannamei sinus gland peptide-G: rLiv-SGP-G) significantly reduced vg mRNA expression in sub-adults after 8h incubation to less than 20% of the control. The concentration of intracellular cyclic guanosine monophosphate (cGMP) increased 3.2-fold relative to the control after 2h incubation with rLiv-SGP-G. However, it reached levels 18-fold relative to the control after 0.5h incubation with rLiv-SGP-G where 3-isobutyl-1-methylxanthine (a phosphodiesterase inhibitor) was also added. Moreover, vg mRNA expression was significantly reduced to less than 50% of the control after 24h incubation with 1μM A23187 (a calcium ionophore). Thus, rLiv-SGP-G and calcium ionophore reduced vg mRNA expression in in vitro-cultured ovary, and cGMP may be involved in the signaling pathway of VIH. Overall, the above results suggest that vg mRNA expression might be inhibited in vitro by increasing intracellular cGMP and Ca2+in L. vannamei ovary.
authors.affiliation: Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki 305-8686, Japan.
authors.forename: Sun-Hye
authors.initials: SH
authors.lastname: Bae
authors.affiliation: Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki 305-8686, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Okutsu
authors.affiliation: Ushimado Marine Institute, Faculty of Science, Okayama University, Setouchi, Okayama 701-4303, Japan.
authors.forename: Naoaki
authors.initials: N
authors.lastname: Tsutsui
authors.affiliation: Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki 305-8686, Japan.
authors.forename: Bong Jung
authors.initials: BJ
authors.lastname: Kang
authors.affiliation: Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki 305-8686, Japan.
authors.forename: Hsiang-Yin
authors.initials: HY
authors.lastname: Chen
authors.affiliation: Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki 305-8686, Japan. Electronic address: marwil@jircas.affrc.go.jp.
authors.forename: Marcy N
authors.initials: MN
authors.lastname: Wilder
mesh_terms: D000818:Animals; D005260:Female; D033561:Penaeidae / Q000737:chemistry*; D015290:Second Messenger Systems; D015398:Signal Transduction; D014819:Vitellogenins / Q000378:metabolism*
chemical_list: D014819:Vitellogenins
keywords: Calcium ionophore; Cyclic AMP; Cyclic GMP; Litopenaeus vannamei; Recombinant sinus gland peptide; Vitellogenin