Expression of vasa (vas)-related genes in germ cells and specific interference with gene functions by double-stranded RNA in the monogenean, Neobenedenia girellae

Hiroshi Ohashi, Naoko Umeda, Noritaka Hirazawa, Yuichi Ozaki, Chiemi Miura, Takeshi Miura

Research output: Contribution to journalArticle

25 Citations (Scopus)


Neobenedenia girellae, a monogenean, is an important pathogen in marine cultured fish such as yellowtail and amberjack. An effective control method is required but none has yet been established. Aiming to establish a new control method by interfering with the gametogenesis of N. girellae, we focused on vasa (vas)-related genes that are expressed exclusively in the germline granules in Drosophila, Caenorhabditis elegans and other animals. Three vas-related genes (N. girellae vasa-like gene, Ngvlg1, Ngvlg2 and Ngvlg3) were isolated by PCR and Ngvlg1 and Ngvlg2 were shown to be expressed only in germ cells. We demonstrated that introduction of double-stranded Ngvlg1 or Ngvlg2 RNA by soaking resulted in partial or complete loss of germ cells. Moreover, the hatching rate of eggs from animals showing partial loss of germ cells decreased significantly. These results suggest that Ngvlg1 and Ngvlg2 are essential genes for germ cell quantity and quality. The possibility that a new control method can be developed by controlling gametogenesis of N. girellae was proven, because sterilised N. girellae could be produced.

Original languageEnglish
Pages (from-to)515-523
Number of pages9
JournalInternational Journal for Parasitology
Issue number5
Publication statusPublished - 2007 Apr
Externally publishedYes



  • In situ hybridisation
  • Monogenea
  • Neobenedenia girellae
  • RNA interference
  • Soaking method
  • Sterilisation
  • vas-related gene

ASJC Scopus subject areas

  • Parasitology
  • Infectious Diseases

Cite this