biostudies-literatureAbu-Elmakarem HUS National Science foundationGordon and Betty Moore FoundationCzech Science Foundationevae262https://www.ebi.ac.uk/biostudies/studies/S-EPMC11635102biostudies-literatureUnknown16(12)The early evolution of eukaryotes and their adaptations to low-oxygen environments are fascinating open questions in biology. Genome-scale data from novel eukaryotes, and particularly from free-living lineages, are the key to answering these questions. The Parabasalia are a major group of anaerobic eukaryotes that form the most speciose lineage of Metamonada. The most well-studied are parasitic parabasalids, including Trichomonas vaginalis and Tritrichomonas foetus, but very little genome-scale data are available for free-living members of the group. Here, we sequenced the transcriptome of Pseudotrichomonas keilini, a free-living parabasalian. Comparative genomic analysis indicated that P. keilini possesses a metabolism and gene complement that are in many respects similar to its parasiticGenome biology and evolutionTranscriptome and Evolutionary Analysis of Pseudotrichomonas keilini, a Free-Living Anaerobic Eukaryote.PMC11635102DEB-2045329GBMF974122-22538SGile GHTaerum SJWilliams TAPetitjean CKotyk MKay CCepicka IAbu-Elmakarem HBass DfalseTranscriptome and Evolutionary Analysis of Pseudotrichomonas keilini, a Free-Living Anaerobic Eukaryote.The early evolution of eukaryotes and their adaptations to low-oxygen environments are fascinating open questions in biology. Genome-scale data from novel eukaryotes, and particularly from free-living lineages, are the key to answering these questions. The Parabasalia are a major group of anaerobic eukaryotes that form the most speciose lineage of Metamonada. The most well-studied are parasitic parabasalids, including Trichomonas vaginalis and Tritrichomonas foetus, but very little genome-scale data are available for free-living members of the group. Here, we sequenced the transcriptome of Pseudotrichomonas keilini, a free-living parabasalian. Comparative genomic analysis indicated that P. keilini possesses a metabolism and gene complement that are in many respects similar to its parasitic2024-01-01T00:00:00Z2024 Dec2026-06-03T00:46:41.726Z2025-04-05T09:28:29.932ZS-EPMC116351023965673310.1093/gbe/evae262