Fig. 1

The general workflow of multiple sequencing approaches adopted in this study. We employed unique dual indexing (UDI) strategy and DNB-based (DNA nanoball) PCR-free MPS platform to minimize index hopping and relevant sequencing errors [41,42,43]. a Amplicon-based enrichment: the UDI was integrated in the 2nd PCR. Navy, multiplex PCR primers. b Metatranscriptomic library preparations: the UDI was integrated in the adaptor ligation and universal PCR steps. c Library preparations and hybrid capture-based enrichment: the UDI was integrated in the adaptor ligation and pre-capture PCR steps. Ocher, ssDNA probes. Red and green lines represent adaptor sequences; green dots represent phosphate groups