title: Silencing of Gonad-Inhibiting Hormone Transcripts in Litopenaeus vannamei Females by use of the RNA Interference Technology.
abstract: The method usually employed to stimulate gonadal maturation and spawning of captive shrimp involves unilateral eyestalk ablation, which results in the removal of the endocrine complex responsible for gonad-inhibiting hormone (GIH) synthesis and release. In the present study, RNAi technology was used to inhibit transcripts of GIH in Litopenaeus vannamei females. The effect of gene silencing on gonad development was assessed by analyzing the expression of GIH and vitellogenin, respectively, in the eyestalk and ovaries of L. vannamei females, following ablation or injection with dsRNA-GIH, dsRNA-IGSF4D (non-related dsRNA), or saline solution. Histological analyses were performed to determine the stage of gonadal development and to assess the diameter of oocytes throughout the experimental procedure. Only oocytes at pre-vitellogenesis and primary vitellogenesis stages were identified in females injected with dsRNA-GIH, dsRNA-IGSF4D, or saline solution. Oocytes at all developmental stages were observed in eyestalk-ablated females, with predominance of later stages, such as secondary vitellogenesis and mature oocytes. Despite achieving 64, 73, and 71% knockdown of eyestalk GIH mRNA levels by 15, 30, and 37 days post-injection (dpi), respectively, in dsRNA-GIH-injected females, the expected increase in ovary vitellogenin mRNA expression was only observed on the 37th dpi. This is the first report of the use of RNAi technology to develop an alternative method to eyestalk ablation in captive L. vannamei shrimps.
authors.affiliation: Molecular Biology Laboratory, Biological Sciences Institute (ICB), Federal University of Rio Grande-FURG, Rio Grande, RS, 96203-900, Brazil.
authors.forename: Rubens G
authors.initials: RG
authors.lastname: Feijó
authors.affiliation: Marine Station of Aquaculture, Oceanography Institute, Federal University of Rio Grande, Rio Grande, RS, 96 201-900, Brazil.
authors.forename: André L
authors.initials: AL
authors.lastname: Braga
authors.affiliation: Molecular Biology Laboratory, Biological Sciences Institute (ICB), Federal University of Rio Grande-FURG, Rio Grande, RS, 96203-900, Brazil.
authors.forename: Carlos F C
authors.initials: CF
authors.lastname: Lanes
authors.affiliation: Molecular Biology Laboratory, Biological Sciences Institute (ICB), Federal University of Rio Grande-FURG, Rio Grande, RS, 96203-900, Brazil.
authors.forename: Márcio A
authors.initials: MA
authors.lastname: Figueiredo
authors.affiliation: Marine Station of Aquaculture, Oceanography Institute, Federal University of Rio Grande, Rio Grande, RS, 96 201-900, Brazil.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Romano
authors.affiliation: Marine Station of Aquaculture, Oceanography Institute, Federal University of Rio Grande, Rio Grande, RS, 96 201-900, Brazil.
authors.forename: Marta C
authors.initials: MC
authors.lastname: Klosterhoff
authors.affiliation: Molecular Biology Laboratory, Biological Sciences Institute (ICB), Federal University of Rio Grande-FURG, Rio Grande, RS, 96203-900, Brazil.
authors.forename: Luis E M
authors.initials: LE
authors.lastname: Nery
authors.affiliation: Center of Studies and Diagnosis of Aquatic Organism Diseases (CEDECAM), Marine Sciences Institute, Federal University of Ceara, Fortaleza, CE, 60165-081, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Maggioni
authors.affiliation: Marine Station of Aquaculture, Oceanography Institute, Federal University of Rio Grande, Rio Grande, RS, 96 201-900, Brazil.
authors.forename: Wilson
authors.initials: W
authors.lastname: Wasielesky
authors.affiliation: Molecular Biology Laboratory, Biological Sciences Institute (ICB), Federal University of Rio Grande-FURG, Rio Grande, RS, 96203-900, Brazil. dqmluf@furg.br.
authors.forename: Luis F
authors.initials: LF
authors.lastname: Marins
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000235:genetics*; D005260:Female; D055785:Gene Knockdown Techniques / Q000379:methods; D020868:Gene Silencing; D007447:Invertebrate Hormones / Q000235:genetics*; D010053:Ovary / Q000166:cytology / Q000254:growth & development*; D010062:Ovulation Induction / Q000379:methods*; D033561:Penaeidae / Q000235:genetics* / Q000254:growth & development; D034622:RNA Interference; D014157:Transcription Factors / Q000235:genetics; D014818:Vitellogenesis / Q000235:genetics*
chemical_list: D002352:Carrier Proteins; D007447:Invertebrate Hormones; D014157:Transcription Factors; C073189:vitellogenesis inhibiting hormone
keywords: GIH; Litopenaeus vannamei; RNAi; RT-qPCR; Reproduction