The Lipidomics of Spermatozoa and Red Blood Cells Membrane Profile of Martina Franca Donkey: Preliminary Evaluation

SIMPLE SUMMARY: Both in human medicine and in the veterinary field, lipidomic techniques have been applied extensively in order to evaluate health status. In equine species where the subject of focus is the fertility and sperm quality of the equids, lipidomic assessment can be a useful tool to better understand the metabolic transformation of the fatty acids of the spermatozoa as well as the erythrocyte membrane and their role on spermiogenesis. The purpose of this study is to evaluate the composition of the spermatozoa’s membranes of 26 healthy male Martina Franca donkeys and the possible correlation with the sperm parameters and the erythrocytes’ membrane. The results demonstrate that the membrane of erythrocytes and spermatozoa are different, which provides a deeper understanding of the distribution and the role of these fatty acids in sperm parameters that are highly associated with fertility. ABSTRACT: Fatty acid-based lipidomic analysis has been widely used to evaluate health status in human medicine as well as in the veterinary field. In equine species, there has been a developing interest in fertility and sperm quality. Fatty acids, being the principal components of the membranes, play an active role in the regulation of the metabolic activities, and their role on spermiogenesis seems to be of great importance for the resulting quality of the sperm and, thus, fertility. With the application of widely used lipidomic techniques, the aim of this study was to evaluate: (a) the fatty acid content of the spermatozoa’s membranes of 26 healthy male Martina Franca donkeys and its possible correlation with sperm parameters, and (b) the evaluation of the composition of the red blood cells’ membrane. PUFA omega-6 are the principal components (40.38%) of the total PUFA content (47.79%) in both types of cells; however, DPA is the predominant one on the spermatozoa’s membrane (27.57%) but is not present in the erythrocyte’s membrane. Spermatozoa’s motility (%) is positively correlated with stearic acid and EPA, and progressive motility (%), with oleic acid. These findings offer information on the composition of both types of cells’ membranes in healthy male MF donkeys and reflect the metabolic transformations of the spermatozoa’s membrane during the maturation period, providing a better perception of the role of fatty acids in sperm parameters and fertility.