Heidelberg researchers introduce reproductive division equipment for synthetic vesicles

Mar 27 2021

One big challenge for making synthetic cells is that they need to be able to separate until they have children. In the magazine Cemie Angewandte, a team from Heidelberg has now introduced reproductive division equipment for synthetic vesicles. It is based on osmosis and can be controlled by enzymatic reaction or light.

Organisms cannot just come from illegal substances (“abiogenesis”), cells always come from pre-existing cells. Synthetic cells raised from the ground up are expected to reverse this pattern. However, one obstacle to this is the issue of controlled segregation – a requirement for “generation”.

A team from the Max Planck Institute for Medical Research in Heidelberg, the University of Heidelberg, Matter to Life School Max Planck, and Exzellenzcluster 3D Matter Made to Order, led by Kerstin Göpfrich, have now reached a milestone by gain full control over the division of the vesicles. To achieve this, they made “gigantic unilamellar vesicles”, which are micrometer-sized bubbles with a shell made of a lipid bilayer that resembles a natural ball. A mixture of lipids has been combined to form partially separated vesicles – vesicles with membrane hemispheres that have different shapes. When the accumulation of dispersed substances in the surrounding solution is increased, osmosis causes water to leave the mouth through the membrane. This reduces the size of the bench while keeping the surface of the organs uniform. The resulting tension at the phase interface deforms the vesicles. They attach themselves to the “equator” – especially with increasing osmotic pressure – until the two halves separate completely into two “daughter cells” (now single- stage) formed by different organs. When the separation occurs only depends on the concentration ratio of osmotically active grains (osmolarity) and is independent of the size of the bench.

The way in which osmolarity is constructed plays no part. The methods used by the team included the use of sucrose solution and the addition of an enzyme that breaks down glucose and fructose to slowly increase the density. Using light to initiate the cleavage of molecules in the solution gave the researchers full spatial and temporal control of their separation. Using tight control, local irradiation allowed the density to be selectively increased around one bench, encouraging it to selectively separate.

The team is also able to grow the single-stage cells back into separated bones by attaching them to tiny bones that have the other type of organ. This was made possible by linking single strands of DNA to both types of organs. These attach to each other and bring the limbs of the daughter cell and the oral cavity tightly connected so that they can melt. The resulting large muscles can go through additional division cycles.

Although these synthetic separation devices are very different from living cell machines. the question arises whether similar mechanisms have played a role in the initiation of life on earth or are involved in the formation of intracellular organisms. ”

Kerstin Göpfrich