Figure 4: Strongyloides-specific expansion and chromosomal clustering of gene families.

(a,b) Astacin-like (a) and SCP/TAPS (b) genes are the two major S. ratti gene families upregulated in the transcriptome of the parasitic female. Left, the phylogeny of each of these gene families for S. ratti, our eight outgroup species and the crayfish Astacus astacus. S. ratti genes are in light blue. Right, the distribution of these genes in the genome, plotted as clusters of physically adjacent genes in the genome. Numbers above the peaks are the number of genes in a cluster of physically neighboring genes; ticks below the axis denote scaffold boundaries for chromosome X. The transcriptomic expression of these genes (in RPKM, reads per kilobase per million mapped reads) for parasitic female (P), free-living female (FL) and iL3 is shown in grayscale, and the results of pairwise edgeR analyses of gene expression for these life cycle stages are shown in color where a gene is upregulated. The color representing upregulation (red or blue) relates to the color of the name of the life cycle stage for each pairwise comparison (fold change > 2, FDR < 0.01); no differential expression is shown as a white block.