Biomedical Informatics Commons^™

Protocol For Unlocking Alternative Polyadenylation Insights From Bulk Rna-Seq Data With Polyaminer-Bulk, Venkata Jonnakuti, Sriya Jonnakuti, Hari Krishna Yalamanchili

Duncan NRI Faculty and Staff Publications

PolyAMiner-Bulk, a deep-learning-based algorithm to decode alternative polyadenylation (APA) dynamics from bulk RNA sequencing (RNA-seq) data, enables scientists to identify and quantify APA events from processed bulk RNA-seq data. The protocol allows researchers to explore differential APA usage between two conditions and gain a better understanding of post-transcriptional regulatory mechanisms. The major steps involve input data preparation, executing PolyAMiner-Bulk, and interpreting the results. A basic familiarity with pre-processing bulk RNA-seq data and command-line tools is suggested.

For complete details on the use and execution of this protocol, please refer to Jonnakuti et al.¹

Diverse Ancestral Representation Improves Genetic Intolerance Metrics, Alexander L Han, Chloe F Sands, Dorota Matelska, Jessica C Butts, Vida Ravanmehr, Fengyuan Hu, Esmeralda Villavicencio Gonzalez, Nicholas Katsanis, Carlos D Bustamante, Quanli Wang, Slavé Petrovski, Dimitrios Vitsios, Ryan S Dhindsa

Duncan NRI Faculty and Staff Publications

The unprecedented scale of genomic databases has revolutionized our ability to identify regions in the human genome intolerant to variation—regions often implicated in disease. However, these datasets remain constrained by limited ancestral diversity. Here, we analyze whole-exome sequencing data from 460,551 UK Biobank and 125,748 Genome Aggregation Database (gnomAD) participants across multiple ancestries to test several key intolerance metrics, including the Residual Variance Intolerance Score (RVIS), Missense Tolerance Ratio (MTR), and Loss-of-Function Observed/Expected ratio (LOF O/E). We demonstrate that increasing ancestral representation, rather than sample size alone, critically drives their performance. Scores trained on variation observed in African and Admixed …

Longitudinal Multi-Omics In Alpha-Synuclein Drosophila Model Discriminates Disease- From Age-Associated Pathologies In Parkinson’S Disease, Justin Moore, Timothy Wu, Justin Dhindsa, Omar El Fadel, Anh Le, Alma Perez, Bismark Amoh, Akash Tarkunde, Katy F Zhu, Matthew Avalos, Eric B Dammer, Duc M Duong, Nicholas T Seyfried, Joshua M Shulman, Ismael Al-Ramahi, Juan Botas

Duncan NRI Faculty and Staff Publications

Parkinson's disease (PD) starts decades before symptoms appear, usually in the later decades of life, when age-related changes are occurring. To identify molecular changes early in the disease course and distinguish PD pathologies from aging, we generated Drosophila expressing alpha-synuclein (αSyn) in neurons and performed longitudinal bulk transcriptomics and proteomics on brains at six time points across the lifespan and compared the data to healthy control flies as well as human post-mortem brain datasets. We found that translational and energy metabolism pathways were downregulated in αSyn flies at the earliest timepoints; comparison with the aged control flies suggests that elevated …

Notch Missense Mutations In Drosophila Reveal Functions Of Specific Egf-Like Repeats In Notch Folding, Trafficking, And Signaling, Hilman Nurmahdi, Mao Hasegawa, Elzava Yuslimatin Mujizah, Takeshi Sasamura, Mikiko Inaki, Shinya Yamamoto, Tomoko Yamakawa, Kenji Matsuno

Duncan NRI Faculty and Staff Publications

Notch signaling plays various roles in cell-fate specification through direct cell–cell interactions. Notch receptors are evolutionarily conserved transmembrane proteins with multiple epidermal growth factor (EGF)-like repeats. Drosophila Notch has 36 EGF-like repeats, and while some play a role in Notch signaling, the specific functions of most remain unclear. To investigate the role of each EGF-like repeat, we used 19 previously identified missense mutations of Notch with unique amino acid substitutions in various EGF-like repeats and a transmembrane domain; 17 of these were identified through a single genetic screen. We assessed these mutants’ phenotypes in the nervous system and hindgut during …

Cancer-Driving Mutations Are Enriched In Genic Regions Intolerant To Germline Variation, Dimitrios Vitsios, Ryan S Dhindsa, Dorota Matelska, Jonathan Mitchell, Xuequing Zou, Joshua Armenia, Fengyuan Hu, Quanli Wang, Ben Sidders, Andrew R Harper, Slavé Petrovski

Duncan NRI Faculty and Staff Publications

Large reference datasets of protein-coding variation in human populations have allowed us to determine which genes and genic subregions are intolerant to germline genetic variation. There is also a growing number of genes implicated in severe Mendelian diseases that overlap with genes implicated in cancer. We hypothesized that cancer-driving mutations might be enriched in genic subregions that are depleted of germline variation relative to somatic variation. We introduce a new metric, OncMTR (oncology missense tolerance ratio), which uses 125,748 exomes in the Genome Aggregation Database (gnomAD) to identify these genic subregions. We demonstrate that OncMTR can significantly predict driver mutations …

A Weakened Recurrent Circuit In The Hippocampus Of Rett Syndrome Mice Disrupts Long-Term Memory Representations, Lingjie He, Matthew S Caudill, Junzhan Jing, Wei Wang, Yaling Sun, Jianrong Tang, Xiaolong Jiang, Huda Y Zoghbi

Duncan NRI Faculty and Staff Publications

Successful recall of a contextual memory requires reactivating ensembles of hippocampal cells that were allocated during memory formation. Altering the ratio of excitation-to-inhibition (E/I) during memory retrieval can bias cell participation in an ensemble and hinder memory recall. In the case of Rett syndrome (RTT), a neurological disorder with severe learning and memory deficits, the E/I balance is altered, but the source of this imbalance is unknown. Using in vivo imaging during an associative memory task, we show that during long-term memory retrieval, RTT CA1 cells poorly distinguish mnemonic context and form larger ensembles than wild-type mouse cells. Simultaneous multiple …