Location of miRNAs in the genome
Of the 188 miRNAs in P. napi , the distribution across autosomes was relatively even, ranging from a single miRNA on chromosome 24 to 12 each on chromosomes 1 and 17, while the Z chromosome, with 35, had many more miRNAs than the autosomes (Figure 1A). The majority were located outside of a gene coding region, with 46 being found before a start codon with an average distance of 15,876 bp (SD ± 25408 bp) and 69 after a stop codon with an average distance of 7,507 bp (SD ± 9924 bp) (Figure 1C). Of the miRNAs located within the boundary of a protein coding gene, the vast majority were located in introns, and 2 on the border of an exon and intron (Figure 1B).