GenomeScope 2.0

GenomeScope 2.0 models k-mer frequency distributions from raw sequencing reads to profile genome characteristics such as genome size, heterozygosity, repetitiveness, and ploidy in heterozygous and polyploid genomes without a reference.

Key Features:

• Polyploid-Aware Mixture Model: Implements a mixture model tailored for polyploid genomes to infer genome size, heterozygosity, and repetitiveness from k-mer frequency distributions.
• Efficiency and Scalability: Processes thousands of simulated datasets and eleven real-world datasets within seconds, demonstrating scalability across a range of genomic complexities.
• Smudgeplots Visualization: Uses Smudgeplots of heterozygous k-mer pairs to visualize and infer ploidy level and genome structural characteristics.
• Application Across Diverse Genomes: Applied to genomes with variable ploidy, including Meloidogyne species and octoploid Fragaria x ananassa.

Scientific Applications:

• Genome assembly support: Provides rapid, reference-free estimates of genome size, heterozygosity, and repetitiveness to inform genome assembly and related analyses.
• Polyploid genomics: Characterizes ploidy and heterozygosity patterns in polyploid organisms using k-mer frequency analysis and Smudgeplots.
• Reference-free genomic profiling: Enables assessment of major genomic characteristics from raw sequencing reads without requiring a reference genome.

Methodology:

Applies combinatorial theory to model k-mer frequency distributions in heterozygous and polyploid genomes and fits a polyploid-aware mixture model to k-mer histograms generated from raw reads counted by tools such as Jellyfish or KMC.