Karnkowska, A., Treitli, S. C., Brzoň, O., Novák, L., Vacek, V., Soukal, P., et al. & Hampl, V. (2019). The Oxymonad Genome Displays Canonical Eukaryotic Complexity in the Absence of a Mitochondrion. Molecular Biology and Evolution 36(10): 2292–2312. doi:10.1093/molbev/msz147.
Key takeaways
From the reading, NOTE-1243.
- Not reduced. About 75 Mb, 16,768 genes and 31,693 introns. It shares more ancestral eukaryotic protein families with Naegleria (83% of its orthogroups) than the parasitic metamonads do.
- Canonical systems. DNA replication and repair, transcription, translation factors, cytoskeleton, membrane trafficking and autophagy look like an ordinary eukaryote’s, apart from traits all metamonads share.
- The organelle was emptied in steps. SUF replaced the mitochondrial Fe–S pathway in all examined Preaxostyla. The glycine cleavage system and SHMT, still in a relative’s organelle, were lost later in this line (THEORY-1098).
- Nothing compensates. Only mitophagy was lost with the organelle, and none of the organism’s unique genes is tied to the loss.
- Caveats. A draft genome and homology searches. The authors do not exclude a highly reduced mitosome below FIB-SEM resolution.
Why this is here
A2’s “2019 genomic analysis” of Monocercomonoides, cited without author or title; identified from the exchange’s description and the abstract. With the 2016 paper it is A2’s negative control.