Animals (May 2020)

Meagre <i>Argyrosomus regius</i> (Asso, 1801) Stem Spermatogonia: Histological Characterization, Immunostaining, In Vitro Proliferation, and Cryopreservation

  • Rosa Zupa,
  • Nicola A. Martino,
  • Giuseppina Marzano,
  • Maria E. Dell’Aquila,
  • Aldo Corriero

DOI
https://doi.org/10.3390/ani10050851
Journal volume & issue
Vol. 10, no. 5
p. 851

Abstract

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The meagre, Argyrosomus regius, is a valued fish species of which aquaculture production might be supported by the development of a stem germ cell xenotransplantation technology. Meagre males were sampled at a fish farm in the Ionian Sea (Italy) at the beginning and end of the reproductive season. Small and large Type A undifferentiated spermatogonia were histologically identified in the germinal epithelium. Among the tested stemness markers, anti-oct4 and anti-vasa antibodies labeled cells likely corresponding to the small single Type A spermatogonia; no labeling was obtained with anti-GFRA1 and anti-Nanos2 antibodies. Two types of single A spermatogonia were purified via density gradient centrifugation of enzymatically digested testes. Testes from fish in active spermatogenesis resulted in a more efficient spermatogonial stem cell (SSC) yield. After cell seeding, meagre SSCs showed active proliferation from Day 7 to Day 21 and were cultured up to Day 41. After cryopreservation in dimethyl-sulfoxide-based medium, cell viability was 28.5%. In conclusion, these results indicated that meagre SSCs could be isolated, characterized, cultured in vitro, successfully cryopreserved, and used after thawing. This is a first step towards the development of a xenotransplantation technology that might facilitate the reproduction of this valuable species in captivity.

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