Amazing stuff! What! Possibly a new species in the tree of life was found?
"... These filament-like organisms, up to a centimetre in length, are the biggest single-cell bacteria yet to be found. ... There are other whoppers in the Thiomargarita bacteria family, but the next-largest is only around 750 micrometres in length. ...
Thiomargarita magnifica is remarkable for more than its size. In other bacteria, genetic material floats freely inside the cell, usually in the form of just one circular chromosome. In T. magnifica, the team saw that the genetic information was stored in hundreds of thousands of pepins [kind of organelle]. Each of these contains DNA and ribosomes, molecular machines that translate instructions from DNA to make proteins. The pepins collectively host up to 700,000 copies of the genome. ..."
Thiomargarita magnifica is remarkable for more than its size. In other bacteria, genetic material floats freely inside the cell, usually in the form of just one circular chromosome. In T. magnifica, the team saw that the genetic information was stored in hundreds of thousands of pepins [kind of organelle]. Each of these contains DNA and ribosomes, molecular machines that translate instructions from DNA to make proteins. The pepins collectively host up to 700,000 copies of the genome. ..."
From the abstract:
"Cells of most bacterial species are around 2 micrometers in length, with some of the largest specimens reaching 750 micrometers. Using fluorescence, x-ray, and electron microscopy in conjunction with genome sequencing, we characterized Candidatus (Ca.) Thiomargarita magnifica, a bacterium that has an average cell length greater than 9000 micrometers and is visible to the naked eye. These cells grow orders of magnitude over theoretical limits for bacterial cell size, display unprecedented polyploidy of more than half a million copies of a very large genome, and undergo a dimorphic life cycle with asymmetric segregation of chromosomes into daughter cells. These features, along with compartmentalization of genomic material and ribosomes in translationally active organelles bound by bioenergetic membranes, indicate gain of complexity in the Thiomargarita lineage and challenge traditional concepts of bacterial cells."
A centimeter-long bacterium with DNA contained in metabolically active, membrane-bound organelles (no public access, here is the preprint)
Pictured next to a one cent coin
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