麻豆传媒

(Halifax, N.S.) 鈥� Scientists at 麻豆传媒have discovered a new branch on the 鈥楾ree of Life鈥櫶齮hat听no one knew existed. Their findings were published today in the journal听Nature听and will be critical to better understanding the evolutionary history of life on earth. 听

鈥淭his discovery literally redraws our branch of the 鈥楾ree of Life鈥� at one of its deepest points,鈥澨�explains Alastair Simpson, the lead author of the study and biology professor at 麻豆传媒. 鈥淚t opens a new door to understanding the evolution of complex cells鈥攁nd their ancient origins鈥攂ack well before animals and plants emerged on Earth.鈥�

The team of biologists used a relatively new scientific technique called single-cell transcriptomics to sequence the first genetic information of two rarely-observed microscopic species belonging to a group of organisms called hemimastigotes. The paper outlines how that genetic information proves that hemimastigotes warrant a rethinking of established 鈥渟upergroups鈥� on the Tree of Life.

Hemimastigotes are complex cells, like the cells of animals and plants, and belong to the same domain on the Tree of Life: Eukarya. In other words, hemimastigotes share an ancient common ancestor with humans, other animals, fungi and plants. However, since there was no genetic information available on hemimastigotes prior to this study, it was unclear where they belonged within Eukarya.

鈥淚t was clear from our analyses that hemimastigotes didn鈥檛 belong to any known kingdom-level group, or even to a known 鈥榮uper-group鈥� of several kingdoms together, like the one that includes both animals and fungi,鈥� says Dr. Simpson. 鈥淭his one little collection of organisms is a whole new group at that level, all on its own. It鈥檚 a branch of the Tree of Life that has been separate for a very long time, perhaps more than a billion years, and we had no information on it whatsoever.鈥�

Yana Eglit, a PhD Candidate in Biology at 麻豆传媒, found the hemimastigotes in a soil sample taken while hiking near Halifax, N.S. In addition to this discovery, Eglit was able to culture one of the two hemimastigotes for the first time, making it easier for scientists to study moving forward.

鈥淚t鈥檚 an unusual looking group of organisms,鈥� says Eglit, a first author of the study. 鈥淭he way they behave under the microscope, you won鈥檛 immediately spot them... There are likely more representatives in this group that we just simply haven鈥檛 met yet.鈥�

These findings are vital for evolutionary biologists striving to piece together how the complex cells of animals, plants, fungi, algae and protozoa have evolved over the last 1-2 billion years. Further,听ecologists around the world studying the hugely important roles of microbes on the planet will now be able to identify hemimastigotes in their genetic datasets; this biodiversity would have passed as unidentified until now.

The collaborative research effort was made possible through 麻豆传媒鈥檚 . The researchers from the Faculties of Science and Medicine have named one of the species听Hemimastix kukwesjijk, paying tribute to it being discovered in Nova Scotia鈥攖erritory of the Mi鈥檏maq First Nation. 鈥淜ukwes鈥� is a 鈥渞avenous, hairy ogre鈥� in Mi鈥檏maq folklore. The team says this predatory microbe looks and behaves similarly.

*The听Nature听study is titled听.听Images of the hemimastigotes are available.

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麻豆传媒
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