This draft genome provides a platform for future research in anthelmintic Ixazomib resistance, drug discovery and vaccine development using H. contortus, currently the most important experimental model for the strongylid nematode group. Results and discussion Genome structure and content We assembled a draft sequence of the H. contortus gen ome based on data from Inhibitors,Modulators,Libraries a mixture of sequencing tech nologies. Our final draft assembly consists of 67,687 contigs linked into 26,044 scaffolds of total length 370 Mb, including 23. 8 Mb of inferred gaps between contigs, with an average and N50 scaffold length of 14,206 and 83,287 bp, respectively. This is a significantly larger gen ome size than the approximately 60 Mb predicted with flow cytometry but it is consistent with a prediction of approximately 200 to 300 Mb inferred from a pilot annotation of two large contiguous regions of the gen ome, making this the largest nematode genome sequenced to date.

The overall base composition of all sequence contigs was close to neutral at a mean 41. 3% GC, slightly higher than that for other Inhibitors,Modulators,Libraries clade V nematodes. Approximately 93% of conserved eukaryotic genes can be identified Inhibitors,Modulators,Libraries in the assembly, suggesting that our draft assembly repre sents at least that fraction of the H. contortus genome, as many of these models are incomplete or split between contigs. Despite this, our current assembly is of similar quality to some other published draft nematode genome sequences. We used Inhibitors,Modulators,Libraries extensive transcriptomic evidence from across the H. contortus lifecycle to guide de novo gene model curation for protein coding genes.

We predict a similar number of protein coding genes to the C. elegans genome, but significantly lower gene density of 59 genes per Mb, with only Inhibitors,Modulators,Libraries 7% of the genome being protein coding, compared to 200 genes per Mb and a protein coding content of approximately 30% in the C. elegans genome. The average coding sequence length is similar in H. contortus and C. elegans but the average gene length is more than double in the parasite. A closer look at a subset of 2,822 H. contortus and C. elegans one to one orthologs shows the discre pancy is explained by an expansion in both the number and length of introns in H. contortus. An expan sion in intronic sequence has also been reported in the closely related necromenic nematode Pristionchus pacifi cus but to a less dramatic extent.

Over 80% of H. contortus and C. elegans one to one orthologs present on the same scaffold occur on the same C. elegans selleck chemicals llc chro mosome, suggesting wide spread conservation of synteny between the two species. However, gene order is generally poorly conserved, which is consistent with comparisons between C. elegans and related nematodes, but regions of conserved microsynteny are apparent and may prove use ful in supporting orthology of divergent genes.