Tracing non-fungal eukaryotic diversity via shotgun metagenomes in the complex mudflat intertidal zones.

Eukaryotes, both micro- and macro-, constitute the dominant component of Earth's biosphere visible to the naked eye. Although relatively big in organismal size, tracing eukaryotic diversity in complex environments is not easy. For example, they may actively escape from sampling and be physically absent from the collected samples. In this study, we strived to recover non-fungal eukaryotic DNA sequences from typical shotgun metagenomes in the complex mudflat intertidal zones. Multiple recently developed approaches for identifying eukaryotic sequences from shotgun metagenomes were comparatively assessed. Considering the low overlap among different approaches, an integrative workflow was proposed. The integrative workflow was then used to recover the eukaryotic communities in complex intertidal sediments. The temporal dynamics of intertidal eukaryotic communities were investigated through a time-series sampling effort. Thirty-four non-fungal eukaryotic phyla were detected from 36 shotgun metagenomes. Clear temporal variation in relative abundance was observed for eukaryotic genera such as