Genetic analysis based on 15 autosomal short tandem repeats (STRs) in the Chaouia population, western center Morocco, and genetic relationships with worldwide populations.

The complex demographic history of human populations in North Africa has resulted in a high degree of genetic heterogeneity across the region. However, little is known about the pattern of these genetic variations in its current populations. The present study provides new data on the genetic background of Chaouia, an Arabic-speaking North African population in the western center of Morocco. A random sample of 150 unrelated healthy individuals from Chaouia was assessed using the AmpFLSTR Identifiler kit. The most polymorphic markers were D21S11 and D18S51, with 23 and 22 alleles, respectively. After Bonferroni's correction, two loci (TH01 and D18S51) deviated from Hardy-Weinberg equilibrium. The phylogeny analysis separated North African populations into northeastern and northwestern groups. The Chaouia population was clustered with northwestern Africans. It was the closest to the Berbers of Azrou. The Chaouia shared close genetic affinities with populations from North Africa, the Middle East, and Europe, particularly Iberians, and to a lesser extent with sub-Saharan populations. The pattern of genetic admixture varied across North African populations without a clear correlation between their geographic (northeastern or northwestern) or linguistic identities (Arab or Berber), however, genetic heterogeneity among Berbers was observed. These findings suggest that the diversity observed in North African populations extends geographical and linguistic boundaries. It is further linked to each population's unique and complex demographic history. Human North African population genetics seems to present an intriguing landscape for future studies in the region and its surrounding populations to trace the origins of the genetic heterogeneity observed in these populations.

Genetic characterization of the Berber-speaking population of Souss (Morocco) based on autosomal STRs.

BACKGROUND: The Souss, located in southern Morocco, is one of the oldest areas of human settlement in North Africa. Despite this historical relevance, the Souss has not received sufficient attention in terms of population genetic studies. METHODS: In this study, we utilized the AmpFlSTR Identifiler PCR amplification system to establish the allelic frequencies and statistical parameters of 15 autosomal STRs (Short Tandem Repeats) in 150 healthy unrelated Berber-speaking individuals from the Souss. We explored the genetic relationships between Souss and other reference populations based on our dataset as well as previously published population data. RESULTS: A total of 210 alleles were detected with corresponding allele frequencies ranging from 0.003 to 0.367. The most polymorphic locus was D18S51 with 23 alleles which was also the most discriminating locus as expected. The phylogenetic analysis clustered the Souss closer to the Azrou and southern Moroccan populations. The population comparison showed affinity between the Souss and most North African populations, as well as with Middle Easterners and Europeans. CONCLUSION: Historical events and geographical proximity have contributed to the affinity between the Souss and surrounding North African, Southern European, and Middle Eastern populations. Overall, this study highlights the reliability of the 15 STRs for identifying individuals and assessing paternity in the Souss population.

Reverse vaccinology-based prediction of a multi-epitope SARS-CoV-2 vaccine and its tailoring to new coronavirus variants.

The genome feature of SARS-CoV-2 leads the virus to mutate and creates new variants of concern. Tackling viral mutations is also an important challenge for the development of a new vaccine. Accordingly, in the present study, we undertook to identify B- and T-cell epitopes with immunogenic potential for eliciting responses to SARS-CoV-2, using computational approaches and its tailoring to coronavirus variants. A total of 47 novel epitopes were identified as immunogenic triggering immune responses and no toxic after investigation with in silico tools. Furthermore, we found these peptide vaccine candidates showed a significant binding affinity for MHC I and MHC II alleles in molecular docking investigations. We consider them to be promising targets for developing peptide-based vaccines against SARS-CoV-2. Subsequently, we designed two efficient multi-epitopes vaccines against the SARS-CoV-2, the first one based on potent MHC class I and class II T-cell epitopes of S (FPNITNLCPF-NYNYLYRLFR-MFVFLVLLPLVSSQC), M (MWLSYFIASF-GLMWLSYFIASFRLF), E (LTALRLCAY-LLFLAFVVFLLVTLA), and N (SPRWYFYYL-AQFAPSASAFFGMSR). The second candidate is the result of the tailoring of the first designed vaccine according to three classes of SARS-CoV-2 variants. Molecular docking showed that the protein-protein binding interactions between the vaccines construct and TLR2-TLR4 immune receptors are stable complexes. These findings confirmed that the final multi-epitope vaccine could be easily adapted to new viral variants. Our study offers a shortlist of promising epitopes that can accelerate the development of an effective and safe vaccine against the virus and its adaptation to new variants.Communicated by Ramaswamy H. Sarma.

Nanobodies: an unexplored opportunity to combat COVID-19.

Coronavirus disease 2019 (COVID-19) is a highly contagious disease caused by severe acute respiratory coronavirus 2 (SARS-CoV-2). This virus is capable of human-to-human transmission, and is spreading rapidly round the globe, with markedly high fatality rates. Unfortunately, there are neither vaccines nor specific therapies available to combat it, and the developments of such approaches depend on pursuing multiple avenues in biomedical science. Accordingly, in this paper we highlight one such avenue-nanobodies-for potential utility in therapeutic and diagnostic interventions to combat COVID-19.Communicated by Ramaswamy H. Sarma.

Results of a collaborative study on DNA identification of aged bone samples.

AIM: A collaborative exercise with several institutes was organized by the Forensic DNA Service (FDNAS) and the Institute of the Legal Medicine, 2nd Faculty of Medicine, Charles University in Prague, Czech Republic, with the aim to test performance of different laboratories carrying out DNA analysis of relatively old bone samples. METHODS: Eighteen laboratories participating in the collaborative exercise were asked to perform DNA typing of two samples of bone powder. Two bone samples provided by the National Museum and the Institute of Archaelogy in Prague, Czech Republic, came from archeological excavations and were estimated to be approximately 150 and 400 years old. The methods of genetic characterization including autosomal, gonosomal, and mitochondrial markers was selected solely at the discretion of the participating laboratory. RESULTS: Although the participating laboratories used different extraction and amplification strategies, concordant results were obtained from the relatively intact 150 years old bone sample. Typing was more problematic with the analysis of the 400 years old bone sample due to poorer quality. CONCLUSION: The laboratories performing identification DNA analysis of bone and teeth samples should regularly test their ability to correctly perform DNA-based identification on bone samples containing degraded DNA and potential inhibitors and demonstrate that risk of contamination is minimized.

Assessment of phylogenetic structure of Berber-speaking population of Azrou using 15 STRs of Identifiler kit.

Allele frequencies for 15 STR autosomal loci of Identifiler kit (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818 and FGA) in the Moroccan population of Berber-speaking of Azrou, were assessed from a sample of 201 unrelated individuals. Markers D18S51, D2S1338, FGA and D21S11 present the highest power of discrimination (PD) values while D21S11 was the most polymorphic locus in the studied population. The phylogenetic tree established among worldwide populations, shows that Berber-speaking population of Azrou was so close to the Berber-speaking population of Asni but also to the Arab-speaking population of southern Morocco. Nevertheless, a significant distance was observed between populations of Azrou and Bouhria even they share the same dialect (Amazigh) and belong to the same geographical area (Morocco). The 15 STR loci studied appear to be highly discriminating, thus providing a powerful tool for forensic applications, paternity investigation, individual identification and anthropological studies.