Sperm DNA fragmentation is referred to as one of the main causes of male infertility. Failures in the protamination process, apoptosis and action of reactive oxygen species (ROS) are considered the most important causes of DNA fragmentation. Action of ROS or changes in sperm protamination would increase the susceptibility of sperm DNA to fragmentation. Routine semen analysis is unable to estimate sperm chromatin damage. Sperm DNA integrity influences sperm functional capability, therefore tests that measure sperm DNA fragmentation are important to assess fertility disorders. Actually, there is a considerable number of methods for assessing sperm DNA fragmentation and chromatin integrity, sperm chromatin stability assay (SCSA modified), sperm chromatin dispersion (SCD), comet assay, transferase dUTP nick end labelling (TUNEL); and protamine evaluation in sperm chromatin assay, such as toluidine blue, CMA3, protamine expression and evaluation of cysteine radicals. This review aims to describe the main causes of sperm DNA fragmentation and the tests commonly used to evaluate sperm DNA fragmentation.

Zygote (Cambridge, England). 2019 Oct 11 [Epub ahead of print]

Thais Rose Dos Santos Hamilton, Mayra Elena Ortiz D’Ávila Assumpção

Animal Reproduction Department, School of Veterinary Medicine and Animal Science, University of São Paulo, SP, Brazil. Av. Prof. Dr. Orlando Marques de Paiva, 87, São Paulo, SP. CEP 05508-270, Brazil.