14 DAY TRIAL // In a new study, scientists managed to identify a type of stress hormone in creatures that lived more than 500 million years ago. The sea lamprey is a jawless animal that could help investigators gain new insight into how corticosteroid hormones came to be, and also into how the human body evolved the 30+ hormones of this type it currently possesses. Using the lampreys, researchers at the Michigan State University (MSU) hope to gain new insights into how the endocrine system – the totality of glands in a living organism – evolved, ScienceDaily reports.
“By identifying 11-deoxycortisol as a stress hormone in lamprey, it allows us to better understand how the endocrine system in vertebrates evolved into the complex systems we see in humans today,” explains MSU professor of fisheries and wildlife Weiming Li. The expert, who is also a member of the Michigan Agricultural Experiment Station, helped lead the investigation into the sea creatures. He explains that corticosteroid hormones are fundamental to the vertebrate body's response to stress. The MSU group is using lampreys as a model for the early endocrine system, he adds.
Over the past years, scientists have studied stress hormones in vertebrates extensively, and managed to gather vast amounts of information on these creatures' endocrine systems. However, they knew very little about what corticosteroids existed in prehistoric creatures, or whether this class of substances was present at all. In a paper the MSU team published in the July 19 issue of the esteemed publication Science, the experts say that the lamprey most likely has a single corticosteroid hormone, as opposed to the humans' 30. The investigation that led to these conclusions was originally targeted at devising new methods for controlling the spread of the parasite.
The lamprey, which originates in the Atlantic Ocean, survives by attaching itself to living fish, and then sucking on its prey's bodily fluids. This means that the creature is capable of killing up to 40 pounds of fish. Annually, authorities spend between $10-15 million on efforts of combating the pest. “Most jawless animals similar to the lamprey didn't survive into the modern era, so they're not available for us to use as we strive to learn more about how human systems developed. The sea lamprey, a survivor, gives us a snapshot of what happened as vertebrates evolved into the animals we know today,” Li concludes.