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Kalita, J.

Publications and source records attributed to Kalita, J..

3 recordsLinked to original sources

HiC-GNN: A Generalizable Model for 3D Chromosome Reconstruction Using Graph Convolutional Neural Networks

Chromosome conformation capture (3C) is a method of measuring chromosome topology in terms of loci interaction. The Hi-C method is a derivative of 3C that allows for genome wide quantification of chromosome interaction. From such interaction data, it is possible to infer the three-dimensional (3D) structure of the underlying chromosome. In this paper, we use a node embedding algorithm and a graph neural network to predict the 3D coordinates of each genomic loci from the corresponding Hi-C contact data. Unlike other chromosome structure prediction methods, our method can generalize a single model across Hi-C resolutions, multiple restriction enzymes, and multiple cell populations while maintaining reconstruction accuracy. We derive these results using three separate Hi-C data sets from the GM12878, GM06990, and K562 cell lines. We also compare the reconstruction accuracy of our method to four other existing methods and show that our method yields superior performance. Our algorithm outperforms the state-of-the-art methods in the accuracy of prediction and introduces a novel method for 3D structure prediction from Hi-C data. Author SummaryWe developed a novel method, HiC-GNN, for predicting the three-dimensional structures of chromosomes from Hi-C data. HiC-GNN is unique from other methods for chromosome structure prediction in that it learns in an eager setting rather than a lazy setting. Thus, the models learned by HiC-GNN can be generalized to unseen data. To the authors knowledge, this generalizing capability is not present in any existing methods. We show that this generalization is robust to input resolution, restriction enzyme, and contact sparsity. We also show that our method outperforms existing methods using both generalized and non-generalized models. Moreover, we also show that our method is more robust to contact variance than the compared methods. AvailabilityAll our source codes and data are available at https://github.com/OluwadareLab/HiC-GNN, and is made available as a containerized application that can be run on any platform.

bioinformatics↗

Draft genome of the liver fluke Fasciola gigantica

Fascioliasis is a neglected food-borne disease caused by liver flukes (genus Fasciola) and affects more than 200 million people worldwide. Despite technological advances, little is known about the molecular biology and biochemistry of the fluke. We present the draft genome of Fasciola gigantica for the first time. The assembled draft genome has a size of ~1.04 Gb with an N50 of 129 kb. A total of 20,858 genes were predicted. The de novo repeats identified in the draft genome were 46.85%. In pathway analysis, all the genes of glycolysis, Krebs cycle and fatty acid metabolism were found to be present, but the key genes for fatty acid production in fatty acid biosynthesis were missing. This indicates that the fatty acid required for the survival of the fluke may be acquired from the host bile. The genomic information will provide a comprehensive resource to facilitate the development of novel interventions for fascioliasis control.

bioinformatics↗

Slow and steady wins the race: encounters of myosin-5 and myosin-6 on shared actin filaments

In the cellular environment multiple myosins use the same filamentous actin (F-actin) tracks, yet little is known about how this track sharing is achieved and maintained. To assess the influence that different myosin classes have on each other, we developed an assay that combines two dynamic elements: elongating actin filaments with identified barbed and pointed ends, and myosins moving along these filaments. We studied two different myosins, myosin-5 and myosin-6. These myosins have distinct functions in the cell and are known to travel in opposite directions along actin filaments. Myosin-5 walks towards the barbed end of F-actin and generally into dynamically rearranging actin at the cell periphery. Myosin-6 is a pointed-end directed myosin that generally walks towards the cell center. We successfully reconstituted simultaneous bidirectional motility of myosin-5 and myosin-6 on single polymerizing filaments of actin. We report and provide statistical analysis of encounters between myosin-5 and myosin-6 walking along the single filaments. When myosin-5 and myosin-6 collide, myosin-5 detaches more frequently than myosin-6. The experimental observations are consistent with a stochastic stepping model based upon known myosin kinetics, which suggests that faster motors are more likely to detach.

biophysics↗