There are some things in the universe that are undeniable truths.
The sky is up, gravity is pulling us down, we can't travel faster than light ... Until now, one of the truths was that multicellular organisms can't survive without oxygen, but from now on we have to be more careful when we say that.
Earlier this year, scientists discovered a parasite that lacks mitochondria. This is the first multicellular organism that has been discovered to lack these cellular organelles, and that also means that it does not breathe, at least not in the way that other multicellular organisms breathe. This parasite lives independently of oxygen.
This discovery changes the understanding of the way organisms can live and function on Earth, but also outside it, writes Science alert.
The body began to develop the ability to breathe about 1.45 billion years ago when a larger archaea protobacterium swallowed a smaller bacterium. Somehow that symbiosis became useful for both sides, so they stayed together. These two organisms evolved together, and this symbiotic relationship led to the bacteria within the archaea becoming mitochondria - organelles necessary for the respiratory process.
Every cell in the human body, except red blood cells, has a large number of mitochondria. Mitochondria break down oxygen to make the molecule adenosine triphosphate, which stores and transports energy inside cells.
Until now, we knew that there are organisms that can adapt to low-oxygen conditions, and that some single-celled anaerobic organisms have created mitochondrial-related organelles during evolution, but the existence of anarobic multicellular organisms has not been discussed. while researchers from Tel Aviv University did not decide to investigate the salmon parasite Henneguya salminocil. It's an incandescent lamp. Žarnjak belongs to the same section as corals, jellyfish and saithe.
These parasites are not harmful and spend the entire life cycle of salmon hooked inside it.
To investigate this parasite, the scientists used deep sequence and fluorescence microscopy. They found that Henneguya salminocyl lost the mitochondrial genome as well as that aerobic respiration capacity and almost all genes involved in mitochondrial transcription and replication were lost. As with unicellular organisms, mitochondrial-associated organelles have evolved in Henneguy salminocytes, but somewhat differently from those in unicellular organisms.Organelles associated with mitochondria in Henneguy salminicola have folds in the inner membrane that are not usually seen.
All these results show that this multicellular organism does not need oxygen to survive in order to breathe.
How he manages to survive is still a mystery to scientists.