Despite the great biological importance of the fusion process, to date no genes and proteins have been identified that work directly in the process
The Technion researchers were able to isolate a gene essential in the fusion process between cells during development. The discovery was published late last week in the prestigious journal Current Biology.
The ability of two cells to fuse into one large cell is essential both for the initial creation of the embryo (fusion between sperm and egg) and for the development of tissues such as the skeleton, muscles and placenta in humans. Despite the great biological importance of the fusion process, to date no genes and proteins have been identified that work directly in the process. In recent years, a group of researchers from the Faculty of Biology at the Technion have been using a small worm called C. elegans as a successful model to begin and decipher the fusion mechanism. During a study carried out two years ago, Dr. Gidi Shemer, under the guidance of Professor Benny Podbilevich from the Faculty of Biology at the Technion and in collaboration with Dr. William Mohler from the University of Connecticut, was able to isolate a gene that is essential for the fusion process. The gene, eff-1, was isolated from worms that failed in the fusion process between different epithelial (skin) cells and was found to code for a protein that acts on the membrane (envelope) of the cells. Now, in the ongoing study, the group of researchers from Prof. Podbilevich's laboratory shows that the gene is not only essential, but also sufficient to nurse cells. To show this, Mittal Suisa, a master's student in the laboratory, together with Dr. Shemer, expressed the gene artificially in cells that do not naturally fuse. This expression resulted in the cells "acquiring" the ability to fuse and unite among themselves, as this was manifested in the disappearance of the envelopes connecting the cells and in the mixing of the intracellular contents. This result is likened to the discovery that one specific key is able to open many different doors, thus testifying to its importance in the "door opening process". In addition, Irena Kolutoyev, a doctoral student in the laboratory, used an electron microscope to follow the fusion attempts in different tissues from worms. This work showed that the eff-1 gene is also essential for the fusion of muscle cells, starting from the stage of creating the first "hole" between the envelopes of the fusing cells until the complete fusion.
"We were able to show, by using worms as a model for developmental questions, that the EFF-1 protein alone can start the fusion process and is essential for its continuation," says Professor Povilevich. "Now, after it is known which gene is the active participant in fusion, the group of researchers at the Technion is concentrating on the question of how it works."
