transdifferentiation

IMMORTAL JELLYFISH — request from elocinbored
Turritopsis nutricula
©Cibermitanios.com.ar

Turritopsis nutricula, the potentially immortal jellyfish, is a hydrozoan whose  jellyfish form can revert back to the polyp stage after becoming sexually mature. It is the only known case of a metazoan capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity.

It does this through the cell development process of transdifferentiation.

Cell transdifferentiation is when the jellyfish “alters the differentiated state of the cell and transforms it into a new cell”. In this process the mature jellyfish transforms back into the polyps stage creating a new polyp colony. Theoretically, this process can go on indefinitely, effectively rendering the jellyfish biologically immortal, although in nature, most Turritopsis, like other medusae, are likely to succumb to predation or disease in the plankton stage, without reverting to the polyp form.

No single specimen has been observed for any extended period, so it is not currently possible to estimate the age of an individual, and so even if this species has the potential for immortality, there is no laboratory evidence of many generations surviving from any individual.

Source: http://en.wikipedia.org/wiki/Turritopsis_nutricula

Other posts:

Purple Striped Jelly

Australian Spotted Jelly

Blood-Red Jelly

22 June 2013

Brain Marrow

Converting one cell type into another – a process called transdifferentiation – doesn’t occur naturally in humans, or in most other creatures for that matter, though it can be induced artificially. But why would researchers want to make a cell switch identities? Well, just imagine if a patient had a disease where certain cells were damaged or dying. Making some of the patient’s other cells adopt the identity of the diseased cells could help to repair or replace the damaged tissue without the need for donor cells or organs. Researchers have now identified an antibody that binds to bone marrow cells and induces them to become nerve cells – their characteristic long skinny projections seen here (stained green) tipped with growth-directing regions called growth cones (stained red). Extracting a person’s bone marrow and converting it into nerve cells could potentially provide a convenient source of cells for repairing brain or spinal cord injury.

Written by Ruth Williams