Abstract

Multiple displacement amplification (MDA) has become one of the most commonly used method of whole genome amplification (WGA) due to the high processivity, strand displacement capacity and high fidelity of the phi29 DNA polymerase, MDA generate vast amount of DNA with higher molecules weight (up to 100kb) and greater genome coverage. Along with the development of the sequencing platform, it is possible to sequence the MDA-amplified DNA molecules with over 20kb by long-read sequencing. However, one of the challenges is the formation of chimeras, which exist in all MDA products, and seriously interfere with the downstream analysis of the long-read sequencing data of MDA-amplified DNA. In this study, we constructed 3rd-ChimeraMiner, a chimera detection pipeline for analyzing the long-read sequencing of MDA products, recognizing chimeras, and integrating chimeras into the downstream analysis. Five sequencing data of MDA with different magnification fold were analyzed in here, the proportions of chimeras are much higher than that of next-generation sequencing reads and increase with the increase of magnification folds, ranging from 42% to over 76%. After comparing, 99.92% of recognized chimeras have been demonstrated not to exist in original genomes. After detecting chimeras by 3rd-ChimeraMiner, the full-length mapping ratio increased, means more PacBio data could be used in downstream analysis, and mean 97.77% inversions were removed after transferred chimeras into normal reads. 3rd-ChimeraMiner revealed efficiency and accuracy in discovering chimeras from long-read sequencing data of MDA, and is promising to be widely used in single-cell sequencing.