Biology (Apr 2024)

Ultrastructural Analysis of Large Japanese Field Mouse (<i>Apodemus speciosus</i>) Testes Exposed to Low-Dose-Rate (LDR) Radiation after the Fukushima Nuclear Power Plant Accident

  • Marta Gatti,
  • Manuel Belli,
  • Mariacarla De Rubeis,
  • Syun Tokita,
  • Hikari Ikema,
  • Hideaki Yamashiro,
  • Yohei Fujishima,
  • Donovan Anderson,
  • Valerie Swee Ting Goh,
  • Hisashi Shinoda,
  • Akifumi Nakata,
  • Manabu Fukumoto,
  • Tomisato Miura,
  • Stefania Annarita Nottola,
  • Guido Macchiarelli,
  • Maria Grazia Palmerini

DOI
https://doi.org/10.3390/biology13040239
Journal volume & issue
Vol. 13, no. 4
p. 239

Abstract

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Since the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, great attention has been paid to the impact of chronic low-dose-rate (LDR) radiation exposure on biological systems. The reproductive system is sensitive to radiation, with implications connected to infertility. We investigated the testis ultrastructure of the wild large Japanese field mouse (Apodemus speciosus) from three areas contaminated after the FDNPP accident, with different levels of LDR radiation (0.29 µSv/h, 5.11 µSv/h, and 11.80 µSv/h). Results showed good preservation of the seminiferous tubules, comparable to the unexposed animals (controls), except for some ultrastructural modifications. Increases in the numerical density of lipid droplet clusters in spermatogenic cells were found at high levels of LDR radiation, indicating an antioxidant activity rising due to radiation recovery. In all groups, wide intercellular spaces were found between spermatogenic cells, and cytoplasmic vacuolization increased at intermediate and high levels and vacuolated mitochondria at the high-level. However, these findings were also related to the physiological dynamics of spermatogenesis. In conclusion, the testes of A. speciosus exposed to LDR radiation associated with the FDNPP accident showed a normal spermatogenesis, with some ultrastructural changes. These outcomes may add information on the reproductive potential of mammals chronically exposed to LDR radiation.

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