Mitochondria are the cell’s power site, transforming energy into a form that the cell can employ for necessary metabolic reactions. These organelles present their own DNA. Although it codes for a small number of genes, mutations in mtDNA are common. Molecular genetics diagnosis allows the analysis of DNA in several areas such as infectiology, oncology, human genetics and personalized medicine. Knowing that the mitochondrial DNA is subject to several mutations which have a direct impact on the metabolism of the mitochondrion leading to many diseases, it is therefore necessary to detect these mutations in the patients involved. To date numerous mitochondrial mutations have been described in humans, permitting confirmation of clinical diagnosis, in addition to a better management of the patients. Therefore, different techniques are employed to study the presence or absence of mitochondrial mutations. However, new mutations are discovered, and to determine if they are the cause of disease, different functional mitochondrial studies are undertaken using transmitochondrial cybrid cells that are constructed by fusion of platelets of the patient that presents the mutation, with rho osteosarcoma cell line. Moreover, the contribution of next generation sequencing allows sequencing of the entire human genome within a single day and should be considered in the diagnosis of mitochondrial mutations.

The vision loss in Leber hereditary optic neuropathy patients is due to mitochondrial DNA mutations. No treatment has shown a clear-cut benefit on a clinically meaningful end-point. However, clinical evidences suggest two therapeutic approaches: the reduction of the mutation load in heteroplasmic patients or the elevation of mitochondrial DNA amount in homoplasmic patients. Here we show that ketogenic treatment, in cybrid cell lines, reduces the percentage of the m.13094 T > C heteroplasmic mutation and also increases the mitochondrial DNA levels of the m.11778G > A mitochondrial genotype. These results suggest that ketogenic diet could be a therapeutic strategy for Leber hereditary optic neuropathy.

Background: Leigh syndrome (LS) is a serious genetic disease that can be caused by mutations in dozens of different genes. Methods: Clinical study of a deafness pedigree in which some members developed LS. Cellular, biochemical and molecular genetic analyses of patients’ tissues and cybrid cell lines were performed. Results: mitochondrial DNA (mtDNA) m.1555A>G/MT-RNR1 and m.9541T>C/MT-CO3 mutations were found. The first one is a well-known pathologic mutation. However, the second one does not appear to contribute to the high hearing loss penetrance and LS phenotype observed in this family. Conclusion: The m.1555A>G pathological mutation, accompanied with an unknown nuclear DNA (nDNA) factor, could be the cause of the phenotypic manifestations in this pedigree.

The Moroccan coast is characterized by a diversity of climate, reflecting a great richness and diversity of fauna and flora. By this, marine microbiota plays a fundamental role in many biogeochemical processes, environmental modifications, and responses to temperature changes. To date, no exploration by high-throughput techniques has been carried out on the characterization of the Moroccan marine microbiota. The objective of this work is to study the diversity and metabolic functions of MMM from the Moroccan coast (Atlantic and Mediterranean) according to the water source (WS) and the type of climate (CT) using the approach high-throughput sequencing of the 16SrRNA gene. Four water samples of twelve sampling sites from the four major climates along the Moroccan coastline were collected, and prokaryotic DNA was extracted. V4 region of 16S rRNA gene was amplified, and the product PCR was sequenced by Illumina Miseq. The β-diversity and α-diversity indices were determined to assess the species richness and evenness. The obtained results were analyzed by Mothur and R software. A total of twenty-eight Bacterial phyla and twelve Archaea were identified from the samples. Proteobacteria, Bacteroidetes, and Cyanobacteria are the three key bacterial phyla, and the Archaeal phyla identified are: Euryarchaeota, Nanoarchaeaeota, Crenarchaeota, Hydrothermarchaeota, Asgardaeota, Diapherotrites, and Thaumarchaeota in the Moroccan coastline and the four climates studied. The whole phylum are involved in marine biogeochemical cycles, and through their functions they participate in the homeostasis of the ocean in the presence of pollutants or stressful biotic and abiotic factors. In conclusion, the obtained results reported sufficient deepness of sequencing to cover the majority of Archaeal and Bacterial genera in each site. We noticed a strong difference in microbiota diversity, abundance, and taxonomy inter- and intra-climates and water source without significant differences in function. To better explore this diversity, other omic approaches can be applied such as the metagenomic shotgun, and transcriptomic approaches allowing a better characterization of the Moroccan marine microbiota and to understand the mechanisms of its adaptation and its impacts in/on the ecosystem.

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.