It is the sea sponge, a colorful and exotic creature that lives at the bottom of the oceans. Her regeneration capacity is so impressive that even if she is crushed in a blender, she can be reborn. “Under ideal conditions, a complete individual can reconstitute itself from minimal cell sets”, says marine biologist Márcio Reis Custódio, from the Department of Biosciences at the University of São Paulo (USP). The ancestors of these animals – which are part of the porifera phylum and can be up to 2 meters tall – emerged 1 billion years ago, a period close to the appearance of the first forms of life on the planet. Next, see what the regeneration process would be like for a sponge torn apart by the propeller of a speedboat.
phoenix of the seas
Sea sponge manages to be reborn from its own “ashes”
1. Even if it is crushed, the sponge will regenerate. This is due, in part, to the simple structure of its organism: without well-developed organs, it is formed by only about 20 types of polyvalent cells, capable of performing various functions (feeding, secretion, etc.)
2. By a mechanism not yet fully understood by science, isolated cells launch projections of their cytoplasm in search of other cells to aggregate
3. In a matter of half an hour, they can regroup into small cell clusters. In these initial aggregates, the cells are simply “glued” to each other, without any kind of functional arrangement.
4. After 48 hours, the aggregate forms a more organized structure, the primorph, which is surrounded by a tissue equivalent to our epidermis. With this “cover”, which isolates the internal environment from the external one, the new sponge can continue its development
5. The primorph seeks to attach itself to a rock – like corals, sponges need to be attached somewhere. He “feels” the rock and, when he sees that he can adhere to it, secretes collagen, forming a thin layer on the surface. That’s where the new sponge will grow
6. During adhesion, the primorph, which was shaped like a ball measuring up to 3 millimeters, flattens to increase the contact surface with the rock, improving its fixation. In the laboratory, adhesion occurs in about 72 hours
7. Tissue regeneration then begins. The cells multiply, forming channels and choanocyte chambers, which are the basic structures of the body of these animals. It is through them that sponges filter sea water and remove nutrients for their survival.
8. As the number of channels and chambers increases, the skeleton begins to appear, which can be made up of collagen, silica or calcium carbonate. In a week, the sponge, still a “little sprout”, is brand new
Is the man?
In mammals, the liver is the organ with the greatest capacity for reconstruction.
1. As soon as a liver is cut in half, cells from both halves begin to proliferate.
2. Some also increase in size, ensuring complete tissue reconstitution
3. The organ returns to shape, but in general it becomes more fibrous as the blood vessels do not fully heal.
resuscitation champions
Check out other animals that are specialists in rebuilding the body
LIZARD
1. To escape from a predator, the gecko amputates its own tail, which keeps moving to divert the enemy’s attention
2. Regeneration begins right after the amputation, through groups of cells capable of organizing themselves into a new tail
3. The vertebrae of the original tail are replaced with cartilage rods and, in about three weeks, the tail is ready
SALAMANDER
1. In addition to its tail, this amphibian can regenerate its legs and even its eyes. After amputation, a layer of epithelial cells covers the wound.
2. A mass of undifferentiated cells – called a blastema – develops just below the epidermis
3. Stem cells from the spine migrate to the site and differentiate into others that will form the muscle and cartilaginous tissue of the leg, which is ready in weeks
Read too:
– How does the lizard’s tail regenerate?
– How does the wound scab form?