Another produces the bile acid precursors that promote the absorption of dietary fat, and a third produces 7-dehydrocholesterol, or 7-DHC. 7-DHC is also generated in many vertebrates. In humans, it has a variety of functions, including essential roles in the production of cholesterol and vitamin D. But high levels of 7-DHC are toxic and are linked to disorders like Smith-Lemli-Opitz syndrome, a rare inherited disease characterized by severe intellectual, developmental and behavioral problems. In octopuses, Dr. Wang and his colleagues suspect that 7-DHC may be the key factor in triggering the self-harming behavior that leads to death.
Roger T. Hanlon, senior scientist at the Marine Biological Laboratory in Woods Hole, Massachusetts, who was not involved in the study, said that “this is an elegant and original study that addresses a long-standing question. date in the reproduction and scheduled deaths of most octopuses.
Dr Wang said that “for us, what was most exciting was seeing this parallel between octopuses, other invertebrates and even humans.” She added that it was “remarkable to see this shared use of the same molecules in animals that are very far apart”.
The molecules may be the same, but death, she says, is very different. We generally view human death as a failure of organ systems or function.
“But in an octopus, that’s not true,” Dr. Wang said. “The system is supposed to do that.”