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Vertebrate reproductive science and technology
RESEARCH ARTICLE (Open Access)

Developing flow cytometry for precise evaluation of amphibian sperm viability: technical report

Leah Jacobs https://orcid.org/0000-0001-5309-1709 A * , Talisin Hammond A , Natalie Calatayud A B C , Patricia Byrne A and Thomas Jensen https://orcid.org/0000-0001-9178-7790 A D
+ Author Affiliations
- Author Affiliations

A San Diego Zoo Wildlife Alliance, Escondido, CA, USA.

B Amphibian Survival Alliance, Mayfield, NSW, Australia.

C Amphibian Specialist Group ARTs and Biobanking Working Group, Mayfield, NSW, Australia.

D Department of Biology, Hobart and William Smith Colleges, 300 Pulteney Street, Geneva, NY 14456, USA.

* Correspondence to: ljacobs@sdzwa.org

Handling Editor: Graeme Martin

Reproduction, Fertility and Development 37, RD24117 https://doi.org/10.1071/RD24117
Submitted: 31 July 2024  Accepted: 16 December 2024  Published online: 14 February 2025

© 2025 The Author(s) (or their employer(s)). Published by CSIRO Publishing. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)

Abstract

Context

In the past decade, flow cytometry has become a useful tool for evaluating cellular viability characteristics for non-domestic animals such as non-human primates, marine animals, and birds. This technology has the potential to vastly improve sperm-quality assessments, concentration counts and cell sorting in a more time-efficient and reliable manner.

Aims

The study aimed to validate the efficacy of using flow cytometry for amphibian sperm by comparing its results with those obtained through traditional means of sperm-quality assessment.

Methods

Sperm samples were collected from testes macerates of the African clawed frog (Xenopus laevis) and subjected to both flow cytometry and microscopy analyses. Flow cytometry allowed for the simultaneous assessment of sperm viability and concentration by using fluorescent probes, whereas microscopy provided a traditional means of assessing sperm characteristics.

Key results

Sperm concentrations measured by flow cytometry and fluorescent microscopy were highly correlated, although flow cytometry methods estimated higher concentrations. Sperm viability measured by flow cytometry and that measured by fluorescent microscopy were not significantly correlated and were significantly different, varying by only ~8% in viability, on average.

Conclusions

Although flow cytometry overestimated concentration and live/dead assessments, the discrepancies were slight enough to indicate that flow cytometry can still be a valuable method for assessing amphibian sperm.

Implications

These results validated the utility of flow cytometry as a reliable tool for assessing amphibian sperm viability and concentration, offering a promising alternative to traditional, time-consuming methods.

Keywords: amphibian, assisted reproductive technology, flow cytometry, fluorescence, sperm, sperm viability, testis, Xenopus.

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