Modification of sperm fatty acid composition during epididymal maturation in bats

Abstract

Biochemical properties of polyunsaturated fatty acids (PUFAs) are fundamental to sperm movements. Amongst all adjustments operated during epididymal maturation, sperm membrane lipid composition is remodelled. Specifically, the proportion of PUFAs usually increases from the caput towards the cauda epididymidis. In mammals, PUFAs are predominantly acquired through the diet, which can consequently impact male fertility. We aimed at analysing to what extent n-6 and n-3 PUFAs are incorporated into sperm in the Seba's short-tailed bat (Carollia perspicillata), and at demonstrating the effect of the sperm fatty acid composition on sperm mobility. We therefore provided food varying in fatty acid composition to males of C. perspicillata and measured the fatty acid composition and mobility traits in spermatozoa collected from the caput and cauda epididymides. We found that n-6 and n-3 PUFAs and saturated fatty acids were significantly related to sperm velocity but not to the proportion of progressive sperm (i.e. motility). Concomitant to an increase in sperm velocity, the level of fatty acid saturation increased from the caput to the cauda epididymidis, while the proportion of PUFAs remained similar along the epididymis. A reduction in n-6 PUFAs counterbalanced an increase in n-3 PUFAs. The food treatments did not affect the sperm fatty acid composition. Our results suggest that a precise endogenous control rather than dietary effects determines sperm fatty acid composition in C. perspicillata.Reproduction (2019) 157 77-85

Relevance of Fatty Acids to Sperm Maturation and Quality

“…Finally, in the Seba's short tailed bat (Carollia perspicillata) concomitant to an increase in sperm velocity, the level of FA saturation increased from the caput to the cauda epididymis, while the proportion of PUFAs remained similar along the epididymis. Food treatments did not affect the sperm FA composition suggesting the presence of a specific endogenous mechanism [35].…”

“…During epididymal maturation, the lipid composition of the sperm membrane is remodeled, where the level of FA saturation is increased from the caput to the cauda epididymis, while the proportion of PUFAs remains similar along the epididymis [35]. The relative content of DHA is higher in epididymal versus testicular sperm in mice [36].…”

Effect of Dietaryn‐3Source on Rabbit Male Reproduction

“…An improper FA profile modifies the function of Sertoli cells as spermatogenesis supporters, influencing germ cell apoptosis [8]. Furthermore, during epididymal maturation, the lipid composition of the sperm membrane is remodelled and the saturation of FA increases from caput to the cauda epididymis, while the proportion of PUFA remains similar [9].…”

A review of the breeding biology of Chiroptera

“…These studies demonstrate a testicular cell pattern in bats similar to that in other mammals, as well as common characteristics among bat species (Álvarez et al 2014, Notini et al 2015, Morais et al 2017. Reproductive capacity was evaluated through the correlation of morphofunctional parameters of the testicles (tubulosomatic index, percentage of testicular cells), environmental variables and body condition, as well as by investigating the effect of the composition of fatty acids on the mobility of sperm (Fasel et al 2018). A few studies have been focused on the participation of reactive oxygen species in sperm physiology; for example, research showed the role of reactive oxygen species in the annual reproductive cycle of Corynorhinus mexicanus (Arenas et al 2007, 2014, Rodríguez-Tobón et al 2015, León-Galvan et al 2017.…”