Vitrification of the ovarian tissue in sturgeons

Jelena Lujić; Roman Franěk; Zoran Marinović; Vojtěch Kašpar; Xuan Xie; Ákos Horváth; Martin Pšenička; Béla Urbányi

doi:10.1016/j.theriogenology.2022.11.009

Vitrification of the ovarian tissue in sturgeons

Theriogenology. 2023 Jan 15:196:18-24. doi: 10.1016/j.theriogenology.2022.11.009. Epub 2022 Nov 7.

Authors

Jelena Lujić¹, Roman Franěk², Zoran Marinović³, Vojtěch Kašpar², Xuan Xie⁴, Ákos Horváth⁵, Martin Pšenička², Béla Urbányi⁵

Affiliations

¹ Cornell University, Department of Biomedical Sciences, Center for Reproductive Genomics, Ithaca, NY, 14850, USA.
² University of South Bohemia in Ceske Budejovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zatisi 728/II, 389 25, Vodnany, Czech Republic.
³ Hungarian University of Agriculture and Life Sciences, Department of Aquaculture, Páter Károly u. 1., H-2100, Gödöllő, Hungary. Electronic address: zor.marinovic@gmail.com.
⁴ Xijing Hospital of Airforce Military Medical University, Department of Gynecology & Obstetrics, Changlexi Road, 710032, China.
⁵ Hungarian University of Agriculture and Life Sciences, Department of Aquaculture, Páter Károly u. 1., H-2100, Gödöllő, Hungary.

PMID: 36375212
DOI: 10.1016/j.theriogenology.2022.11.009

Abstract

The aim of this study was to test whether vitrification of sterlet Acipenser ruthenus and Russian sturgeon Acipenser gueldenstaedtii ovarian tissue through needle-immersed vitrification (NIV) is an efficient strategy for the preservation of oogonia (OOG) in order to supplement the current conservation efforts for these endangered fish species. Histological analyses of the gonads displayed that the ovaries of both species were immature and contained predominantly OOG and primary oocytes. The germline origin of these cells was verified by localization of the vasa protein through immunocytochemistry. NIV protocol was optimized by testing different equilibration (ES) and vitrification solutions (VS) containing various concentrations of dimethyl sulfoxide (Me₂SO), propylene glycol (PG) or methanol (MeOH). In sterlet, the highest average viability (55.7 ± 11.5%) was obtained by using a combination of 1.5 M PG and 1.5 M Me₂SO in the ES, and 1.5 M MeOH and 5.5 M Me₂SO in the VS. In Russian sturgeon, the highest average viability (49.4 ± 17.1%) was obtained by using a combination of 1.5 M MeOH and 1.5 M Me₂SO in the ES, and 3 M PG and 3 M Me₂SO in the VS. To test whether vitrified/warmed OOG are functional, we have conducted an intra-specific transplantation assay to verify whether transplanted sterlet OOG will colonize the gonads of recipient fish. Fluorescently labelled cells were detected within recipient gonads at 2 and 3 months post-fertilization (mpf). Colonization rates of vitrified/warmed OOG (70% at 2 mpf and 61% at 3 mpf) were similar to those of fresh OOG (80% at 2 mpf and 70% at 3 mpf). This study has demonstrated that vitrification of ovarian tissue is an effective method for the preservation of OOG, and that the vitrified/warmed cells are functional and are able to colonize recipient gonads after transplantation similarly to the fresh cells. Since the vitrification procedure displayed in this study is simple and does not require complex and expensive laboratory equipment, it can be readily applied in field conditions, and therefore it can be invaluable for the conservation efforts of the critically endangered sturgeon species. However, care needs to be taken that despite the research conducted so far, donor-derived progeny was not yet obtained in sturgeons.

Keywords: Acipenseriformes; Cryopreservation; Germ cells; Oogonia; Ovarian stem cells.

MeSH terms

Animals
Fishes
Ovary*
Vitrification*