Female octopuses mutilate each other to death after mating

It is difficult to know when the life of a person or any other animal will end. However, with the octopus females it’s a little easier. Once they mate, their end is near. wait lay the eggs and almost immediately afterwards a macabre process begins in which the skin and tentacles are torn off bite By the time their little octopuses come into the world, they have already lost their lives. It’s something that has caught the attention of scientists for years, because it’s unclear why or how they do it. However, a team of researchers from University of Chicago I may have an answer for the second question.

And it is that, according to the study that has just been published in Current biology, the key is in cholesterol metabolism. We usually talk about this substance in relation to food and its effects on health. But the truth is that it is linked to many processes. In fact, it is necessary for our survival (and also for octopuses), but always at adequate levels and with a metabolism that adjusts to certain limits. Otherwise, in the process hazardous substances may be generated or such harmful effects as the suicide of the female octopuses.

All this seems to be linked to a little-known organ of these cephalopods: the optic gland. This would be almost equivalent to our pituitary, but after mating, it has a dangerous effect on female octopuses. Let’s see how they came to this conclusion.

Behind the Suicide of Female Octopuses

optic gland was discovered in 1977. Then it was observed that it is involved in several processes, such as sexual development and aging, both octopus and squid. But what most caught the attention of scientists who began studying it was that if the females were removed, they did not tend to commit suicide after mating.

To find out why, in 2018 a study was launched based on RNA sequencing of two female octopuses at different stages of their decline. But why did they sequence RNA instead of DNA? Mainly because they didn’t want to know what genes they had, but what genes they use.

RNA gives us information about which genes are “in use” at any given time

All cells of an animal have the same DNA. However, each of them will use the genes you need for your needs, which may also vary depending on the circumstances. That’s what we call gene expression.

For to carry these genes the code must translate into protein. However, the organelles responsible for it, called ribosomes, cannot read the information contained in DNA. They can only read RNA, so DNA sequences to express are transcribed into RNA.

Therefore, if we sequence RNA, we will have information about which genes are using in certain cells at a certain time. In this case, it is the cells of the female octopus optic gland. They found that as death approached, activity increased in genes that control sex hormones, insulin-like hormones, and cholesterol metabolism.

This was the first stage of the investigation. Now, however, some of these scientists have gone further, focusing directly on the molecules secreted in each case.


The role of cholesterol

In humans, we know that some cholesterol precursors They are toxic at high levels. For this reason, there are some genetic disorders associated with increased cholesterol metabolism which can cause a wide variety of symptoms due to the accumulation of these substances. Among them are the repetitive self-harm.

Therefore, when these scientists saw in the study the role of Cholesterol metabolism in the optic gland of the female octopus they knew they might be close to answering the mystery of their self-destruction.

Some cholesterol precursors can be very toxic in large amounts

All that remained was to observe the evolution of the molecules secreted by these animals at different stages. This was the final stage of the study that has just been published and it served to see that indeed, when mated, they increase secretion of sex hormones, insulin-like hormones and cholesterol precursors. These precursors that are so toxic in humans.

Until now, the optic gland was only associated with sexual signaling pathways, but this detail was not known. There is a little more light on the mystery, even if the big question remains unanswered: why female octopus self destruct after laying her eggs? Maybe some humans (hopefully not many) think they’ve already fulfilled their function as women. But octopuses are very intelligent animals. Surely there will be another explanation. Now is the time to try to find out.