Biology Forums - Study Force

The turriptosis dornii is the only animal that can revert back to its youth once it has reached a certain age. I certainly don't know the process under which this is made possible, but I'd like to research a little bit about it before I go to college and see if anyone with experience or a degree can help. So... can it somehow be applied to humans through say an injection or some sort of pill to mimic the chemical process biological process which this jellyfish undergoes?

Thank you in advance for your help.

They're considered "immortal" because they can revert from a free-swimming form to the polyp stage, forming a new polyp colony. It does this through the cell development process of transdifferentiation, which alters the differentiated state of the cells and transforms them into new types of cells.

Transdifferentiation is a process in which one mature somatic cell gets transformed, into another mature somatic cell without having any intermediate pluripotent state or progenitor cell type.

It is an irreversible change of one type of differentiated cell to another type. Transdifferentiation is related to a specific change in the program of gene expression and it has direct ancestor-descendant relationship among the two cell types . At the molecular level, transdifferentiation is a change in the expression of a master switch gene (selector or homeotic gene), usually, whose normal function is to distinguish the two cell types in normal development.

Most cells in the human body are already differentiated during fetal development, hence it's impossible.

So it lives its whole life with undifferentiated cells?

When the jellyfish is an adult, its cells are committed to that phase and are differentiated. Something that I didn't mention which I should mentioned earlier is that transdifferentiation is a subcategory of metaplasia.

When cells face physiological or pathological stress, they adopt several ways to overcome that stress, metaplasia is one of the way. It is a reversible transformation (both forward and backward transformation) of one differentiated cell type to another differentiated cell type. It may be a part of normal maturation process, or may be due to some abnormal stimulus or factors. If the original cells are not strong enough to face the stresses by their environment, they transform into another cell type which is more suitable for that state. If the stimulus or factor causing metaplasia is removed or stopped, the tissues returns to its normal mode of cell differentiation.

Excellent! I hope to learn more and maybe one day apply what I know somehow in the practical applications of dohrnii into the human body. Is it completely impossible?

Not completely impossible. Researchers have successfully reprogrammed somatic cells to a pluripotent state by using embryonic stem cells. Earlier experiments in cell fusion and nuclear transfer showed that gene expression in differentiated cells remained dynamic and reversible. Silent genes in a specific cell type can be reactivated by fusing the cells with a different cell type. Subsequently, several studies showed that introduction of defined transcription factors could convert specialized cell types from one lineage to another. When somatic cells were reprogrammed by transferring their nuclei into oocytes or by fusion with ES cells, genome-wide transcriptional activity and DNA methylation patterns were converted from the somatic state to an embryonic state.

In 2006, Kazutoshi Takahashi and Shinya Yamanaka established for the first time murine ES-like cell lines from mouse embryonic fibroblasts (MEFs) and skin fibroblasts by simply expressing four transcription factor genes encoding Oct4, Sox2, Klf4, and c-Myc (Figure 1) (Takahashi & Yamanaka 2006). They called these somatic cell-derived cell lines induced pluripotent stem (iPS) cells. These iPS cell lines exhibit similar morphology and growth properties as ES cells and express ES cell-specific genes. Transplantation of iPS cells into immunodeficient mice resulted in the formation of germ-cell-tumor (teratoma)-containing tissues from all three germ layers, confirming the pluripotent potential of iPS cells. However, there were two problems: the low efficiency of establishing iPS cell lines and some variations in gene expression profiling between iPS cells and ES cells. The latter issue raised the concern that cell reprogramming may be insufficient to restore full pluripotency in somatic cells as exhibited by ES cells.