A mouse made with a gene older than animal life

    The current theory of evolution tells us that all life had to evolve from an ancestor and that different species may share a common ancestor. Even the split between unicellular organisms and multicellular organisms had to have had a common ancestor at some point in time. 

    Dr. Alex de Mendoza of Queen Mary University of London and a team of researchers from the University of Hong Kong ventured out to see if a gene found in choanoflagellates could be used to make stem cells to produce a living mouse. Choanoflagellates were chosen since they are the closest single-celled organism related to animals as well as having a version of the Sox and POU genes, genes responsible for the development of different cell types found within animals. The team put the choanoflagellate Sox and POU genes into mouse cells to replace the native Sox and POU genes, producing stem cells. The stem cells made were essentially codes that which were overwritten by the new Sox and POU genes. These stem cells were then injected into a mouse embryo resulting in a living, breathing mouse that had physical traits belonging to the donor embryo and the new stem cells. What this confirmed was that the Sox and POU genes, genes older than animal life, were essential parts of the puzzle for animal life to even exist.

    The implications of this discovery are incredible. The fact that a single-celled organism has genes vital for multicellular life to exists is interesting as it implies these genes might have not originally served the role we as humans use them for. It's possible they were meant to serve a different purpose entirely and some change or mutation resulted in the evolution of the multicellular organism since the Sox and POU genes in choanoflagellates are not exactly the same as the animal version. I find it really interesting how one discovery can make us question what we know about genetics and how much we actually understand.

How to Set Up Protozoan Mating Swarm, Bacteria Style

At the University of California, Berkeley, scientists were researching Salpinogoeca rosetta cells when they suddenly began to form mass mating swarms after exposure to an aphrodisiac produced by a bacteria. The bacteria in question that created the aphrodisiac was Vibrio fischeri. The bacterium creates chonodroitin sulfate (CS) lyase, in which is then released as a chemical signal that causes the cells to quickly aggregate and begin cell and nuclear fusion while duplicating and recombining their genetic material. 

According to researchers, Nicole King and Ariel Woznica, this discovery has led to researchers to believe the possibility that environmental bacteria or bacterial symbionts can influence mating in animals as well. Part of the research at Berkeley was exploring the origins of multicelluarlarity. The research was mostly conducted on choanoflagellates such as the S. rosetta cells. Generally, researchers would monitor shared characteristics and behaviors that was common for evolution in animals. Based on the research, scientists have discovered symbiotic and pathogenic relationships between bacteria and multi-cellular animals. This relationship has been dated to even prehistoric times.

With this research, choanoflagelletes can serve as an excellent model organism in order to discover more information regarding the origins of multicelluarlity. By using these organisms, it can have an advantageous adaptation and uses in medicine. Supposedly, researchers can use choanoflagelletes as a means of mass drug production for cures by instilling the gene for the drug. By using bacteria to induce the cells to mass mating, it can cause a rapid supply of drugs based on a natural process within bacteria. This can certainly be very useful in the field of medicine.   

A Single Mutation May Have Sparked Multicellular Life

An important change in our ancestor’s DNA occurred millions of years ago. Life consisted of unicellular organisms a long time ago, and million cells arose from the fusion of two, ten and many cells. As a result, different types of cells led to the rise of organisms, which laid the path for the formation of tissues, organs and ultimately life. Researchers from the Oregon university believed that a single mutation directed in the transition from single-celled organisms to multi cellular organisms when they traced back the steps of evolution through phylogenetic tree. During mitosis, two daughter cells produced within the tissue are placed in proper orientation. Mitotic spindles align daughter cells with protein markers on the cell wall.  Cancer is the result of improper orientation of spindles and malformed tissue. The origin of multi cellular life can be pinpointed if researchers would discover the ancient protein structures that has the ability to position spindles.

Choanoflagellates are the closest unicellular relatives to animals and because they are unicellular, they organize into colony to feed on food. Multiple cells perform a single task as how the organs function. As a result, the need for the genetic change emerged along the way that allow single cells to identify each other and come together. Researchers need to do molecular time travelling to trace this watershed moment. Ancestral protein reconstruction technique combines gene sequencing with computer algorithms to duke into millions of years in the past. Researchers were able to distinguish when mutations took place in more than 40 organisms by working through a chain. The technique allowed them to create cells with the same DNA. They identified a single mutation that changed the way certain proteins function with the help of resurrected cells.

 The altered proteins(enzymes) became an interaction domain which can communicate and link to other proteins. This crucial protein today is present in all animal genomes and is put to work when a cell divides every time. This mutation is a small change that intensely changed the protein’s function, thus allowing it to do an entirely different task. According to Ken Prehoda, “animals really like these proteins because there are now over 70 of them inside of us.” The findings of team could lead to innovative insights about cancer and additional diseases. Cancer cells, lone wolves, misbehave and stop to communicate with body cells. By considering how cells communicate could help us understand why they stop. A small change can sometimes have huge consequences.

I found this article interesting because it discusses how the single mutation led to the origin of multi-cellular organisms from unicellular. The ancient protein structures allowed the multi-cellular organisms to arise by tracing back to the phylogenetic tree. The mutation altered the protein’s structure, and as a result can provide insights about cancer disease in which the cancerous cells do not communicate with body cells, and they arise because of improper spindle orientation during mitosis. The ancient proteins are the source of communication and linkage to other proteins. Cancer can be curable if we are able to identify how cells communicate.

http://blogs.discovermagazine.com/d-brief/2016/01/12/a-single-mutation-may-have-sparked-multicellular-life/#.V_E10PkrLIW

http://www.futurity.org/mutation-multicellular-life-1088352-2/