Nassar, J. | bioRxiv Science

bioRxiv2026

A genome language model for mapping DNA replication origins

Origin firing is a central process during DNA replication, but specific sequences defining replication origin usage have not been defined in human cells. Here, we show that a genome language model can accurately predict which sequences can act as an origin of replication, thereby enabling the fast and cost-effective creation of genome-wide replication origin maps. We fine-tuned a genome language model on the primary sequence of mapped human origins to establish ORILINX (ORIgin of replication Language-model Inference via Nucleotide conteXt) and found that it learns a rich representation of sequence features linked to replication initiation, extending beyond known predictive features such as GC-content and G-quadruplex motifs. When applied genome-wide, the models sequence-derived origin calling closely mirrors origin efficiency inferred from replication timing, suggesting that intrinsic sequence context encodes information relevant to initiation frequency. Furthermore, we performed Short Nascent Strand sequencing (SNS-seq) and Repli-seq to demonstrate that ORILINX can generalise to other mammalian genomes, such as those of mice and sheep, as well as other vertebrates such as chickens. Finally, we packaged ORILINX into a simple, easy-to-use tool which is available at https://github.com/Pfuderer/ORILINX.git.

genomics↗

bioRxiv2023

Multiepitope-based vaccine design against DiiA in Streptococcus pneumoniae, An immunoinformatics approach.

Streptococcus pneumoniae (SPN) infection has resulted in significant morbidity and mortality worldwide in children and adults. It is responsible for colonizing the human nasopharynx and can also cause diseases, including otitis media, pneumonia, bacteraemia, and meningitis. SPN is exhibiting resistance to multiple antibiotics and current vaccines have a number of limitations including poor immunogenicity and limited effectiveness against all pneumococcal serotypes. Here, we explain the design of a novel multi-epitope vaccine using Dimorphic invasion-involved protein A (DiiA) as a target protein. For designing the vaccine, the sequence of DiiA was obtained and various bioinformatics tools were employed to predict multiple CTL, HTL, B lymphocyte epitopes of DiiA. After evaluating antigenicity, allergenicity, toxicity, and immunogenicity, the most promising epitopes were chosen for constructing the vaccine, followed by an analysis of their physicochemical and immunological characteristics.The prediction, refinement, and validation of the 3D structure of the vaccine were carried out. Molecular docking, molecular dynamic simulation, and immune simulation were executed to examine the binding affinities and biological interactions at the atomic level between the vaccine and Toll-like receptor (TLR4). Vaccine translation, codon optimization were performed and expression efficiency was assessed through an in-silico cloning experiment performed to transfer into pET28a(+) plasmid vector.The obtained results proved that the vaccine maintained structural stability and possessed the capability to stimulate an efficient immune response against S. pneumoniae infection. The constructed vaccine has the potential for subsequent wet lab experimentation, leading to the development of an innovative vaccine.

bioinformatics↗