Data and code from: Evidence for balancing selection on loci associated with host use in the genome of a generalist plant parasite
Data files
Sep 10, 2026 version files 166.78 KB
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1.fastq_to_vcf.zip
16.56 KB
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2.pop_structure.zip
9.97 KB
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3.genome_scan.zip
31.77 KB
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4.selection_inference.zip
15.11 KB
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5.fastsimcoal2.zip
38.89 KB
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6.ARGweaver.zip
10.74 KB
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7.SO.zip
7.80 KB
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8.GO_analysis.zip
8.69 KB
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9.cwd_eff.zip
25.37 KB
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README.md
1.88 KB
Abstract
Most research on host-parasite interactions has focused on tightly coevolved species pairs, yet many parasites are generalists that infect a wide range of host taxa. Generalist parasites are subject to highly variable selection pressures across different hosts and the footprints that this heterogeneous selection leaves in the genomes of generalists have been largely unexplored. To address this knowledge gap, we studied patterns of host-associated genetic diversity in the generalist plant parasite, the northern root knot nematode Meloidogyne hapla. By leveraging whole genome amplification, we generated whole genome libraries of individual root-knot nematodes collected from three different host plant species in a spatially replicated design. Despite finding no evidence of host-associated population structure, we did observe several hundred host-associated SNPs putatively under differential host selection. Genomic regions containing these host-associated SNPs were enriched for signals of balancing selection. Consistent with balancing selection, polymorphisms originated earlier in genomic windows that contained a host-associated SNP compared to those that did not. Additionally, host-associated SNPs were enriched for functions involved in plant pathogenesis, specifically the modification of plant cell walls. Host-associated SNPs were also found in genes with known roles in dampening host plant immune responses to infection. Together, our results suggest a model of balancing selection in which heterogeneous selection by different host taxa maintains adaptive diversity at loci involved in pathogenesis.
The code in this repository is split out by analysis. There are additional README files in each repo to provide brief overviews of which each script does. Below is a brief outline of what is contained in each directory.
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1.fastq_to_vcf.zip - Contains scripts to align raw fastq files and call variants along with several QC and filtering steps.
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2.pop_structure.zip - Contains code to perform population structure analyses
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3.genome_scan.zip - Contains scripts to perform genome-wide scans for host-associate SNPs
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4.selection_inference.zip - Contains scripts to perform inferences on selection, mainly Tajima's D
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5.fastsimcoal2.zip - Contains scripts to perform demographic inference using fastsimcoal2
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6.ARGweaver.zip - Contains scripts to estimate ancestral recombination graphs to estimate locus-specific TMRCAs
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7.SO.zip - Contains scripts to perform sequence ontology enrichment tests
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8.GO_analysis.zip - Contains scripts to perform GO-term enrichment tests
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9.cwd_eff.zip - Contains scripts to perform selection inferences on known cell wall degrading enzymes and effectors
Code/Software
Note on languages needed to run these analysis:
All analyses were performed using R, python and command-line programs executed through Bash in a Linux environment. The analyses for the study were run on a high-performance computing cluster (HPC), although an HPC environment is not necessarily required to execute individual scripts. All analyses were performed on a high performance cluster in a linux environment. All programs used in this study are open source and freely available. Specific software packages, libraries, and command-line programs required for each analysis are indicated in the corresponding scripts.
Access Information
All data for this repo can be downloaded from SRA on NCBI: Bioproject PRJNA1437807
