# Effects of ultraviolet B radiation and cold storage on Ram sperm morphology and physiology

**Authors:** Daniele S de S. Cestaro, Antonio Sergio Varela Junior, Anthony Valverde, Ana Paula de Souza Votto, Daza de Moraes Vaz Batista Filgueira, Marc Yeste, Carine Dahl Corcini

PMC · DOI: 10.1007/s00484-025-03082-4 · International Journal of Biometeorology · 2026-02-02

## TL;DR

This study examines how UVB radiation and cold storage affect the structure and function of ram sperm, finding that UVB causes damage but cold storage does not.

## Contribution

The study provides new insights into the specific effects of UVB radiation on ram sperm morphology and physiology.

## Key findings

- UVB exposure damaged the acrosome but left the plasma membrane and DNA intact.
- Cold storage at 5°C for 24 and 48 hours did not significantly affect sperm structures.
- Sperm motility decreased with UVB exposure but some motility was retained.

## Abstract

Ultraviolet B radiation damages DNA increases oxidative stress and impairs fertility and survival in organisms. The spermatozoa are particularly vulnerable, experiencing altered structure, function, and fertilization capacity due to UVB exposure. The objective of the present study was to evaluate the effects of ultraviolet B radiation and cold storage on the morphology and physiology of ram spermatozoa. The samples of fresh semen from seven animals, obtained during six collections, yielded 42 ejaculates. Aliquots were diluted in Tris egg yolk and were subjected to varying doses of UVB radiation, namely no radiation (0 mJ/cm2), 2.199 mJ/cm2, 4.398 mJ/cm2, 6.597 mJ/cm2, 8.796 mJ/cm2, and 10.995 mJ/cm2. All evaluations were carried out in duplicate and immediately after UVB exposure; samples were also stored at 5 °C for analysis at 24 and 48 h. Sperm were evaluated for motility using a computer assisted sperm analysis system (CASA), apart from plasma membrane integrity, mitochondrial function, DNA integrity, and acrosomal fluorescence. While UVB exposure damaged the acrosome, the plasma membrane and DNA remained intact. Storage at 5 °C for 24 h and 48 h did not affect any of the structures studied, and even though certain aspects of sperm kinematics were affected, they retained motility. Thus, exposure to UVB resulted in lower sperm motility and structures without completely damaging the sperm.

## Full-text entities

- **Genes:** VCL [NCBI Gene 101121312], STATH (statherin) [NCBI Gene 6779] {aka STR}
- **Diseases:** necrosis (MESH:D009336), mitochondrial damage (MESH:D028361), cytotoxicity (MESH:D064420)
- **Chemicals:** CPDs (MESH:D011740), DAP (MESH:C041756), PI (MESH:D011419), ethyl alcohol (MESH:D000431), CFDA (MESH:C027780), ROS (MESH:D017382), ozone (MESH:D010126), Acridine Orange (MESH:D000165), phospholipid (MESH:D010743), cholesterol (MESH:D002784), H2O (MESH:D014867), lipid (MESH:D008055), Rh123 (MESH:D020112), formaldehyde (MESH:D005557), Arachis hypogaea - FITC (-), sodium citrate (MESH:D000077559)
- **Species:** Rattus norvegicus (brown rat, species) [taxon 10116], Ovis aries (domestic sheep, species) [taxon 9940], Mus musculus (house mouse, species) [taxon 10090], Eisenia fetida (brandling worm, species) [taxon 6396], Macrobrachium olfersii (species) [taxon 249258], Homo sapiens (human, species) [taxon 9606], Oncorhynchus mykiss (rainbow trout, species) [taxon 8022]

## Full text

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## Figures

2 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12864269/full.md

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Source: https://tomesphere.com/paper/PMC12864269