Have we conquered sperm morphology analysis in different mammalian species as analysed by CASMA?

Gerhard van der Horst, Stefan S. du Plessis, Liana Maree

Department of Medical Biosciences, University of the Western Cape, Bellville, South Africa; Department of Basic Sciences, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates; Division of Medical Physiology, Stellenbosch University, Tygerberg, South Africa

Abstract: Computer-aided sperm morphology analysis (CASMA) advanced to a level where it is possible to analyse sperm morphology of most mammalian laboratory animals (rat and mouse), domestic animals (bull, boar, ram, goat, horse, dog and cat) and wildlife species (e.g. African elephant, African white rhinoceros, African buffalo, leopard, cheetah, lion, wild dog, several antelope species). The Sperm Class Analyzer (SCA) CASMA is capable of analysing all major sperm components, including the acrosome, head, midpiece and tail, provided that the correct staining technique has been used. In this context, a stain which is isotonic and isosmotic as well as producing a clear background for analysis is preferred. In CASA systems such as the SCA, a large number of morphometric parameters are measured, including detailed facets such as roughness, smoothness and regularity. However, one of the major challenges faced with CASMA for animals is to provide cut-off values for so-called normal sperm morphology, for both diverse species and different breeds in the domestic market. Accordingly, a combination of CASMA morphometric parameters and visual analysis by experienced investigators has been used to define cut-off values for normal sperm morphology for a given species. In this investigation, sperm morphometry and the definition of normal sperm morphology will be discussed for a number of species, with emphasis on the methodology of performing such analyses quantitatively in Wistar rat, bull, Tankwa goat, hyrax and several other mammalian species. This paper provides invaluable information on what constitutes normal sperm morphology when assessed objectively and highlights the importance of sperm indices such as TZI (teratozoospermic index) as well as many other quantitative aspects.

van der Horst G., du Plessis S.S., Maree L. (2021) Have We Conquered Sperm Morphology Analysis in Different Mammalian Species as Analysed by CASMA?. In: Björndahl L., Flanagan J., Holmberg R., Kvist U. (eds) XIIIth International Symposium on Spermatology. Springer, Cham. https://doi.org/10.1007/978-3-030-66292-9_38
First Online: 23 July 2021