Fig. 1

Overview of ViLR workup strategy. ViLR is a novel virtual NGS-based long-link read method, firstly developed for de novo PGT-SR carriers’ haplotype phasing without a proband. (1) Specifical sample and barcoded bead labeling. First, HMW gDNAs were extracted from de novo chromosomal rearrangement carriers. Long gDNAs were inserted by transposome-transposon, and linked with tags-marked barcoded beads. After inactivating the transposome and adding the adapters, short DNA fragments with the same tags were generated. Finally, libraries were built by PCR amplification. (2) Breakpoint identification and direct SNP haplotyping of carriers. After sequencing, a long read gDNA with the same tags could be assembled; different long read molecules differently tagged were simultaneously generated and aligned for mapping to the reference genome. Sufficient informative SNPs were collected for breakpoint characterization and haplotype phasing. (3) Haplotype determination of embryos. Blastocysts were subjected to biopsy and WGA. After genome library construction, sequencing and SNP calling, embryonic haplotypes could be directly identified based on the established carriers’ haplotype phasing