DNA sequences of extraction and library preparation negative controls
Extraction negative control: Dabney et al. (2013) protocol with modifications added according to Morales-Arce et al. (2017); Library negative control: after a partial UDG treatment described in Rohland, et al. (2015), libraries were prepared using the protocol described in Care, et al. (2018); the negatives and sample were indexed using a unique pair of DNA barcodes