The RNAs present in spermatozoa play a crucial role in reproduction and embryonic development. They represent a promising diagnostic tool for assessing male infertility. However, their extraction is challenging due to their low concentration and highly condensed chromatin structure, as well as the presence of numerous cellular contaminants. These challenges vary across species and require the development of an optimized and reliable isolation method to obtain high-quality RNAs, which is essential for further molecular analyses regarding the roles played by these RNAs. This study evaluated two RNA extraction methods for spermatozoa in humans and other mammals (dogs, stallions, and bulls): a standard method using the NucleoSpin RNA® II kit (Macherey-Nagel) and an optimized method that combined this kit with dithiothreitol and TRIzol™ pretreatment. In addition, the samples underwent pre-purification to eliminate somatic cells. The optimized method produced a significantly higher total RNA yield along with better purity, which was confirmed by the absence of the 18S and 28S ribosomal RNA peaks, indicating the absence of somatic cell contamination. Additionally, RT-PCR was performed to validate the presence of sperm-specific markers. The quality of the extracted RNAs was assessed by sequencing the mRNA encoding the human olfactory receptor OR1D2 and observing the resulting band on an agarose slab gel with a size corresponding to its entire open reading frame. By addressing long-standing challenges in sperm RNA isolation, our method provides an easy and standardized technique for research in reproductive biology and for advancing our understanding of paternal contributions to transgenerational inheritance.
Male infertility, implicated in nearly 50% of couples’ infertility cases, represents a major medical and sociocultural challenge in Morocco. This narrative review synthesizes available epidemiological, etiological, and genetic data within national and international contexts. In Morocco, male infertility is characterized by the frequent involvement of modifiable factors, notably varicocele, smoking, and occupational exposures. From a genetic standpoint, chromosomal abnormalities, particularly Klinefelter syndrome, together with Y chromosome microdeletions, especially within the AZFc region, represent the main identified etiologies. Emerging technologies, such as next-generation sequencing, offer promising diagnostic perspectives, although their clinical application remains limited and mainly confined to research. Despite advances in medically assisted reproduction, the management of male infertility in Morocco continues to face psychosocial and economic barriers, as well as inequalities in access to care. These findings underscore the need to establish national registries, conduct multicenter studies, and facilitate the translation of innovations (particularly multi-omics approaches) into clinical practice to improve male infertility management in the Moroccan context.