Complex Bacterium Writes New Evolutionary Story

“Finding nuclear pore-like structures in the bacterial species Gemmata obscuriglobus is significant for understanding how the cell nucleus and the pores embedded in its membrane envelope could have evolved – a major unsolved problem in evolutionary cell biology.”

Professor Fuerst said the bacterium, which was first isolated from Maroon Dam in South-East Queensland in 1984 by UQ researchers Dr Peter Franzmann and Professor Vic Skerman, now constituted one of the most complex bacteria known.

He said the finding suggested that the evolution of complex cell structures may not be unique to eukaryotes, which are organisms containing a nucleus and other structures (organelles) encased in a membrane.

“The research finding is consistent with previous data my lab has published indicating that the Gemmata obscuriglobus bacterium contains a nuclear body compartment, which parallels the eukaryote nucleus.”

Professor Fuerst said the discovery was important for understanding how the first complex cells may have originated.

“The results are of evolutionary significance, since the origin of eukaryotes is a major event in life’s history,” he said.

Professor Fuerst said nuclear pore complexes (NPCs) were important in transporting molecules between the nucleus containing the DNA and the rest of the cell contents in eukaryote organisms such as protozoa, fungi, animals and plants.

“They are dotted over the surface of the membranes separating the nucleus from the rest of the cell and enable communication between the nucleus and other parts of the cell,” he said.

“Like the membrane-bounded nucleus, NPC’s had been thought to be restricted to eukaryotes.”

The researchers used a combination of techniques including advanced electron microscopy, a protein analysis method called proteomics, and bioinformatics genome analysis to make the discovery.