library_construction_protocol: Genomic DNA was extracted from sorted and unsorted populations using Qiagen Puregene kit according to manuacture's protocol. Total genomic DNA was amplified by PCR with Huclease II polymerase using guide-specific primers, oMCB_1562 5'-aggcttggatttctataacttcgtatagcatacattatac-3' and oMCB_1563 5'-ACATGCATGGCGGTAATACGGTTATC-3'. Like samples were pooled and used as template for a second PCR in which Illumina adaptors (5'-caagcagaagacggcatacgagatgcacaaaaggaaactcaccct-3') and barcodes were added to the samples.