bioRxiv Science⌕ Search

Biology subjects

Mazzotti, G.

Publications and source records attributed to Mazzotti, G..

3 recordsLinked to original sources

VirNA: a novel Minimum Spanning Networks algorithm for investigating viral evolution

Next Generation Sequencing technologies are essential in public health surveillance for tracking pathogen evolution, spread, and the emergence of new variants. However, the extensive sequencing of viral genomes during recent pandemics has highlighted the limitations of traditional molecular phylogenetic algorithms in capturing fine-grained evolutionary details, emphasizing the urge for more effective approaches to manage these large-scale data. VirNA (Viral Network Analyzer) addresses this challenge by reconstructing detailed mutation patterns and tracing pathogen evolutionary routes in specific regions through Minimum Spanning Networks. It analyzes thousands of sequences, generating networks where nodes represent identical genomic sequences linked to their metadata, while edges represent evolutionary pathways. AUTHOR SUMMARYThe authors present Viral Network Analyzer (VirNA), a new tool designed to help track the spread of viruses during pandemics. During recent outbreaks, researchers faced challenges due to the sheer volume of viral genome data. Traditional tools struggled to process this massive amount of information effectively. VirNA solves this problem by using a powerful method called Minimum Spanning Networks (MSN) with enhanced features to analyze large datasets quickly and accurately. VirNA allows scientists to map how viruses spread in specific areas, providing critical insights that other tools couldnt achieve. It complements traditional phylogenetic methods, offering a detailed look at viral transmission routes. This makes it a valuable asset for public health surveillance, helping experts understand and respond to pandemics more effectively. Already tested in previous studies, VirNA represents a significant breakthrough for future pandemic preparedness, offering new ways to handle and interpret big data in viral research.

bioinformatics↗

Magnetic Activation of Spherical Nucleic Acids for the Remote Control of Synthetic Cells

The advancement of synthetic cells as drug delivery devices hinges on the development of targeting strategies, in particular the controlled synthesis of biomolecules in-situ using a deeply penetrative stimulus. To address this, we have designed spherical nucleic acids comprising DNA promoter sequences decorating magnetic nanoparticle cores. By harnessing the heat dissipated from magnetic hyperthermia (a clinically-approved anticancer therapy) we tightly controlled cell-free protein synthesis. We then deployed a tissue phantom that is impenetrable by current activation methods to demonstrate the potential of this technology for the remote control of synthetic cells using deeply tissue-penetrating magnetic fields. This paves the way for targeting and controlling the in-situ synthesis of biomolecules deep within the body. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=181 SRC="FIGDIR/small/608917v1_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@3cf352org.highwire.dtl.DTLVardef@18a8da3org.highwire.dtl.DTLVardef@159018aorg.highwire.dtl.DTLVardef@744529_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗

Rapid longitudinal SARS-CoV-2 intra-host emergence of novel haplotypes regardless of immune deficiencies

On February 2020, the municipality of Vo, a small town near Padua (Italy), was quarantined due to the first coronavirus disease 19 (COVID-19)-related death detected in Italy. The entire population was swab tested in two sequential surveys. Here we report the analysis of the viral genomes, which revealed that the unique ancestor haplotype introduced in Vo belongs to lineage B and, more specifically, to the subtype found at the end of January 2020 in two Chinese tourists visiting Rome and other Italian cities, carrying mutations G11083T and G26144T. The sequences, obtained for 87 samples, allowed us to investigate viral evolution while being transmitted within and across households and the effectiveness of the non-pharmaceutical interventions implemented in Vo. We report, for the first time, evidence that novel viral haplotypes can naturally arise intra-host within an interval as short as two weeks, in approximately 30% of the infected individuals, regardless of symptoms severity or immune system deficiencies. Moreover, both phylogenetic and minimum spanning network analyses converge on the hypothesis that the viral sequences evolved from a unique common ancestor haplotype, carried by an index case. The lockdown extinguished both viral spread and the emergence of new variants, confirming the efficiency of this containment strategy. The information gathered from household was used to reconstructs possible transmission events. AUTHOR SUMMARYIt is of great interest and importance to understand SARS-CoV-2 ability to mutate generating new viral strains, and to assess the impact of containment strategies on viral transmission. In this study we highlight the rapid intra-host haplotype evolution regardless of symptom severity and immune deficiencies that we observed during the first wave of the pandemic in the municipality of Vo in Italy. The confirmation that all the haplotypes found in this small community derive from a common ancestor haplotype, has allowed us to track the rapid emergence of new variants but lockdown and mass testing efficiently prevented their spread elsewhere.

evolutionary biology↗