Fig. 3

Schematic diagram showing methodology of the genome subtraction pipeline a A hypothetical schematic of the B. duperreyi sex chromosomes with the male specific gene region indicated in blue (not to scale); b Low coverage whole genome sequencing was conducted on an Illumina platform resulting in approximately 8X coverage; c The raw sequencing reads are decomposed into 27 base pair k-mers d The k-mer spectrum is plotted and sequences with low counts are removed; e Female k-mers are subtracted from the male k-mers. Male specific k-mers are retained and then assembled into putative Y-chromosome contigs; f Primers are designed on putative male contigs. g PCR sex test and validation (image shown here is for illustrative purposes only; refer to Fig. 1 and the original gel images in Additional Data 2 for the definitive data)