Ailable. Instead, we adapted the iterative approach used by Holt et al.59. In our implementation, the pan-CEP-37440MedChemExpress CEP-37440 genome was initiated as the nucleotide sequences predicted for the genes of the first genome used (the input order of genomes was randomised). The nucleotide sequences of the genes for the genome in the next iteration (Gi) was then compared with the pan-genome using MUMmer (Nucmer algorithm, parameters used were: -forward -l 20 -mincluster 20 -b 200 -maxmatch)60. The results of the MUMmer analyses were parsed to capture gene pairs which shared greater than 95 homology. Homology was calculated as the average of percent PD-148515 site sequence identity, the percent coverage of the query sequence by the reference, and the percent coverage of the reference sequence by the query. This list of nodes (genes) and edges (homology) was then used as input data for the graph building algorithm, MCL61. The resulting graphs were explored to identify genes in Gi which shared a graph with genes already present in the pan-genome – these genes were excluded, however the number of times a gene was matched to the existing pan-genome was found in additional genomes was recorded. All genes not sharing graphs with genes already present in the pan-genome were added to the pan-genome for use in the next iteration. After each genome had been compared with the pan-genome, we performed an amalgamation step to attempt to detect genes which, in draft genomes, had been split over multiple contigs. To do this, we compared the pan-genome against itself using MUMmer under the same parameters as previously specified. In this case, however, we recorded gene pairs when the following criteria were met: i) the length of the query sequence was less than 80 of the length of the reference sequence, ii) the length of the reference sequence was greater than 120 the length of the query sequence, iii) the alignment identity was greater than 95 , iv) the coverage of the reference by the query sequence was greater than 20 , and v) the coverage of the reference by the query sequence was less than 80 . When these criteria were met, we defined the query sequence as `part-of ‘ the reference. These pairs were then passed to MCL for graph building. For each graph, the longest gene which could be detected in three or more individual genomes was captured as the representative gene for the graph, all other genes were discarded. This step was designed to detect the longest representative of a set of gene parts when that representative could be reliably detected. This detection threshold of three separate genomes was selected in order to limit the possibility that gene fusions created by sequencing error (which may be expected to be very rare within the genes of each graph) would be chosen to replace `true’ genes, whilst allowing full length representatives of genes split over contigs (which may be expected to be more common, since at least some of the genomes within our sample originate from completely sequenced isolates) to be recovered. Finally, the repaired genes in the pan-genome were again compared against themselves using MUMmer, under the same parameters as before. This time, gene pairs were assigned when two genes shared greater than 80 homology (homology was again defined as the average of percent identity, percent coverage of the reference by the query, and percent coverage of the query by the reference). These pairs were passed to MCL for a final round of graph building, and a single repre.Ailable. Instead, we adapted the iterative approach used by Holt et al.59. In our implementation, the pan-genome was initiated as the nucleotide sequences predicted for the genes of the first genome used (the input order of genomes was randomised). The nucleotide sequences of the genes for the genome in the next iteration (Gi) was then compared with the pan-genome using MUMmer (Nucmer algorithm, parameters used were: -forward -l 20 -mincluster 20 -b 200 -maxmatch)60. The results of the MUMmer analyses were parsed to capture gene pairs which shared greater than 95 homology. Homology was calculated as the average of percent sequence identity, the percent coverage of the query sequence by the reference, and the percent coverage of the reference sequence by the query. This list of nodes (genes) and edges (homology) was then used as input data for the graph building algorithm, MCL61. The resulting graphs were explored to identify genes in Gi which shared a graph with genes already present in the pan-genome – these genes were excluded, however the number of times a gene was matched to the existing pan-genome was found in additional genomes was recorded. All genes not sharing graphs with genes already present in the pan-genome were added to the pan-genome for use in the next iteration. After each genome had been compared with the pan-genome, we performed an amalgamation step to attempt to detect genes which, in draft genomes, had been split over multiple contigs. To do this, we compared the pan-genome against itself using MUMmer under the same parameters as previously specified. In this case, however, we recorded gene pairs when the following criteria were met: i) the length of the query sequence was less than 80 of the length of the reference sequence, ii) the length of the reference sequence was greater than 120 the length of the query sequence, iii) the alignment identity was greater than 95 , iv) the coverage of the reference by the query sequence was greater than 20 , and v) the coverage of the reference by the query sequence was less than 80 . When these criteria were met, we defined the query sequence as `part-of ‘ the reference. These pairs were then passed to MCL for graph building. For each graph, the longest gene which could be detected in three or more individual genomes was captured as the representative gene for the graph, all other genes were discarded. This step was designed to detect the longest representative of a set of gene parts when that representative could be reliably detected. This detection threshold of three separate genomes was selected in order to limit the possibility that gene fusions created by sequencing error (which may be expected to be very rare within the genes of each graph) would be chosen to replace `true’ genes, whilst allowing full length representatives of genes split over contigs (which may be expected to be more common, since at least some of the genomes within our sample originate from completely sequenced isolates) to be recovered. Finally, the repaired genes in the pan-genome were again compared against themselves using MUMmer, under the same parameters as before. This time, gene pairs were assigned when two genes shared greater than 80 homology (homology was again defined as the average of percent identity, percent coverage of the reference by the query, and percent coverage of the query by the reference). These pairs were passed to MCL for a final round of graph building, and a single repre.
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