instaGRAAL

instaGRAAL performs chromosome-level scaffolding by using Hi-C contact frequencies to order and orient contigs and produce improved genome assemblies.


Key Features:

  • Hi-C data utilization: Uses Hi-C contact frequencies to bridge gaps between contigs and infer proximity for scaffolding into chromosome-scale assemblies.
  • Markov Chain Monte Carlo (MCMC) algorithm: Employs an MCMC probabilistic algorithm for modeling genomic contact data during scaffolding.
  • Modular polishing: Provides a modular polishing strategy that can integrate independent datasets to refine assemblies.
  • Scalability for large genomes: Incorporates improvements intended to facilitate handling of large genomes.
  • CUDA GPU acceleration: Performs certain operations that rely on CUDA for GPU-accelerated computation.

Scientific Applications:

  • Chromosome-level genome scaffolding: Converts draft contig assemblies into chromosome-scale assemblies for genome assembly projects using Hi-C data.
  • Brown algae genome assembly: Has been applied to generate chromosome-level assemblies for Desmarestia herbacea and Ectocarpus sp., showing improvements over initial draft assemblies.

Methodology:

Performs Hi-C-based scaffolding using a Markov Chain Monte Carlo algorithm, integrates a modular polishing step that can use independent datasets, builds on the principles of GRAAL, and uses CUDA for certain GPU-accelerated operations.

Topics

Details

License:
GPL-3.0
Tool Type:
command-line tool, library
Programming Languages:
Python
Added:
1/14/2020
Last Updated:
12/14/2020

Operations

Publications

Baudry L, Marbouty M, Marie-Nelly H, Cormier A, Guiglielmoni N, Avia K, Mie YL, Godfroy O, Sterck L, Cock JM, Zimmer C, Coelho SM, Koszul R. Chromosome-level quality scaffolding of brown algal genomes using InstaGRAAL, a proximity ligation-based scaffolder. Unknown Journal. 2019. doi:10.1101/2019.12.22.882084.