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Sola, L.

Publications and source records attributed to Sola, L..

3 recordsLinked to original sources

Eduomics: a Nextflow pipeline to simulate -omics data for education

Moving past learning just algorithms and code is a key challenge of bioinformatics education: the ideal goal is for students to acquire higher-order knowledge such as the ability to solve biological problems with the appropriate tools, and more importantly learn to interpret the results in the broader context where bioinformatics is needed. To design such a teaching and learning experience, data simulations play a key role: however, there is a massive barrier to adoption. Different data types are produced by different tools, requiring educators to learn each of them and adapt their workflow to the necessary dependencies, requirements and input files. Additionally, most existing data simulation solutions are meant for benchmarking and methods development rather than education and cannot provide the context needed to teach students the critical interpretation skills they need to move beyond problem-based learning to what we call storyline-based learning. A significant effort must be placed also when many datasets with the same characteristics are needed, such as in tutoring or assessment in higher education. Here, we present eduomics: a Nextflow pipeline meant to automate the simulation workflow for both genomic and transcriptomic next-generation sequencing data, and to produce realistic clinical scenarios to provide students with clues and a biomedical story necessary for the interpretation of their results. Eduomics removes barriers to adoption, by requiring the user to just decide which chromosome datasets should be simulated on, and which type of data they would like to simulate. There is no need to learn specific tools and resolve their dependencies. The use of Gemini API provides an innovative approach to generate plausible clinical scenarios, consistent with the genes where either a pathological mutation or differential expression has been simulated. With eduomics, we offer an accessible and scalable solution to design comprehensive learning experiences and innovate bioinformatics education. Author SummaryModern bioinformatics education faces a dual challenge: students must learn how to analyse data and interpret results within the biological problems they aim to solve, while instructors who wish to design such a comprehensive learning experience should introduce appropriately simulated data in their teaching. However, the complexity of existing simulation tools is an often daunting barrier to overcome: current solutions require different software for different data types and provide no support for teaching interpretation skills. Most available simulators were designed for benchmarking and method development, not for education: therefore they lack the biological and clinical context needed to move beyond the traditional problem-based learning. To address these challenges, we developed eduomics, a Nextflow-based end-to-end pipeline that automates the simulation of genomic and transcriptomic data in a fully automated manner for educational use. Educators only need to choose the type of data to simulate, while the pipeline handles all underlying tools and dependencies. As a groundbreaking element, we integrated the Google Gemini API to generate patient-inspired clinical scenarios that gives students realistic clues and a biomedical narrative in which to interpret the results. This approach complements the traditional problem-based learning by offering a more complete, storyline-based learning experience. By combining automated data simulation and clinical storytelling, eduomics provides an accessible and scalable solution that support an engaging and immersive learning experience for both educators and students.

bioinformatics↗

TERRA transcripts and promoters from telomeric and interstitial sites

The transcription of human telomeres gives rise to a family of long noncoding RNAs, named TERRA. We previously showed that TERRA transcription is driven by CpG island promoters that are composed by stretches of three types of repeats. Using the human genome assembly that was available at that time, putative promoter sequences were localized at several subtelomeres. In this work, using the T2T-CHM13v2.0 human reference genome, we found that 39 out of 46 subtelomeres contain TERRA promoters and grouped them in classes depending on their organization. We then discovered 106 intrachromosomal TERRA-like promoters, adjacent to interstitial telomeric sequences (ITSs) or far away from them. Fortyseven of these promoters are flanked and may regulate the transcription of coding genes, ncRNAs or pseudogenes. Comparative sequence analysis showed that interstitial and subtelomeric promoters belong to a previously undescribed family of segmental duplications deriving from common ancestral sequences. RT-PCR experiments in seven cell lines demonstrated that TERRA transcripts can be synthesized from ITSs. TERRA expression was always low in primary fibroblasts and HeLa cells while highly variable in the other two telomerase positive (HT1080 and HEK293) and in the three telomerase negative ALT cell lines (GM847, U2OS and VA13). The analysis of RNA-seq data from U2OS, HeLa and HEK293 cells showed that 205 ITSs were transcribed in at least one cell lines. The fraction of transcribed ITSs and the level of their transcription increased with the length of the telomeric repeat stretch. Given the large number of transcribed ITSs, we propose that these loci contribute significantly to the production of the TERRA pool.

molecular biology↗

Neocentromere formation through Robertsonian fusion and centromere repositioning during the evolution of zebras

Centromeres are epigenetically specified by the histone H3 variant CENP-A and typically associated to highly repetitive satellite DNA. We previously discovered natural satellite-free neocentromeres in Equus caballus and E. asinus. Here, through ChIP-seq with an anti-CENP-A antibody, we found an extraordinarily high number of centromeres lacking satellite DNA in the zebras E. burchelli (15 of 22) and E. grevyi (13 of 23), demonstrating that the absence of satellite DNA at the majority of centromeres is compatible with genome stability and species survival and challenging the role of satellite DNA in centromere function. Nine neocenstromeres are shared between the two species in agreement with their recent separation. We de novo assembled all neocentromeric regions and improved the reference genome of E. burchelli. Sequence analysis of the CENP-A binding domains revealed that they are LINE-1 and AT-rich with four of them showing DNA amplification. In the two zebras, satellite-free centromeres emerged from centromere repositioning or following Robertsonian fusion. In five chromosomes, the centromeric function arose near the fusion points, which are located within regions marked by traces of ancestral pericentromeric sequences. Therefore, besides centromere repositioning, Robertsonian fusions are an important source of satellite-free centromeres during evolution. Finally, in one case, a neocentromere was seeded on an inversion breakpoint. At eleven chromosomes, whose primary constrictions seemed to be associated to satellite repeats by cytogenetic analysis, neocentromeres were instead located near the ancestral inactivated satellite-based centromeres, therefore, the centromeric function has shifted away from a satellite repeat containing locus to a satellite-free new position.

genomics↗