iScience (Jan 2023)

Sex-inducing effects toward planarians widely present among parasitic flatworms

  • Kiyono Sekii,
  • Soichiro Miyashita,
  • Kentaro Yamaguchi,
  • Ikuma Saito,
  • Yuria Saito,
  • Sayaka Manta,
  • Masaki Ishikawa,
  • Miyu Narita,
  • Taro Watanabe,
  • Riku Ito,
  • Mizuki Taguchi,
  • Ryohei Furukawa,
  • Aoi Ikeuchi,
  • Kayoko Matsuo,
  • Goro Kurita,
  • Takashi Kumagai,
  • Sho Shirakashi,
  • Kazuo Ogawa,
  • Kimitoshi Sakamoto,
  • Ryo Koyanagi,
  • Noriyuki Satoh,
  • Mizuki Sasaki,
  • Takanobu Maezawa,
  • Madoka Ichikawa-Seki,
  • Kazuya Kobayashi

Journal volume & issue
Vol. 26, no. 1
p. 105776

Abstract

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Summary: Various parasitic flatworms infect vertebrates for sexual reproduction, often causing devastating diseases in their hosts. Consequently, flatworms are of great socioeconomic and biomedical importance. Although the cessation of parasitic flatworm sexual reproduction is a major target of anti-parasitic drug design, little is known regarding bioactive compounds controlling flatworm sexual maturation. Using the planarian Dugesia ryukyuensis, we observed that sex-inducing substances found in planarians are also widespread in parasitic flatworms, such as monogeneans and flukes (but not in tapeworms). Reverse-phase HPLC analysis revealed the sex-inducing substance(s) eluting around the tryptophan retention time in the fluke Calicophoron calicophorum, consistent with previous studies on the planarian Bipalium nobile, suggesting that the substance(s) is likely conserved among flatworms. Moreover, six of the 18 ovary-inducing substances identified via transcriptome and metabolome analyses are involved in purine metabolism. Our findings provide a basis for understanding and modifying the life cycles of various parasitic flatworms.

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