A new form of microbial life

Two species of the microscopic organisms, called hemimastigotes, were found in dirt collected on a whim during a hike in Nova Scotia by Dalhousie University graduate student Yana Eglit. A genetic analysis shows they're more different from other organisms than animals and fungi (which are in different kingdoms) are from each other, representing a completely new part of the tree of life, Eglit and her colleagues report this week in the journal Nature.

Hemimastigotes were first seen and described in the 19th century. But at that time, no one could figure out how they fit into the evolutionary tree of life. Consequently, they've been "a tantalizing mystery" to microbiologists for quite a long time, Eglit said.

Like animals, plants, fungi and ameobas — but unlike bacteria — hemimastigotes have complex cells with mini-organs called organelles, making them part of the "domain" of organisms called eukaryotes rather than bacteria or archaea.

About 10 species of hemimastigotes have been described over more than 100 years. But up until now, no one had been able to do a genetic analysis to see how they were related to other living things. Realizing that she had something very rare and special, Eglit flagged another graduate student Gordon Lax, who specializes in genetic analyses of individual microbes — a new and tricky technique — to see where they fit in the evolutionary tree. The pair dropped everything to analyze the new microbe.

Based on the genetic analysis they've done so far, the Dalhousie team has determined that hemimastigotes are unique and different enough from other organisms to form their own "supra-kingdom" — a grouping so big that animals and fungi, which have their own kingdoms, are considered similar enough to be part of the same supra-kingdom.

https://www.cbc.ca/news/technology/hemimastigotes-supra-kingdom-1.4715823