Although the prize expired, unclaimed, long ago, University of New Hampshire professor of biochemistry Stacia Sower and colleagues at two Japanese universities have identified the first reproductive hormone of the hagfish – a gonadatropin -- representing a significant step toward unraveling the mystery of hagfish reproduction.
Their findings, “Evolutionary origin of a functional gonadotropin in the pituitary of the most primitive vertebrate, hagfish,” were published in the journal Proceedings of the National Academies of Science (PNAS) in September.
“This is a significant breakthrough with hagfish,” says Sower, who was second senior author on this paper, co-authored by principal investigator Katsuhisa Uchida and Sower’s long-time collaborator Masumi Nozaki, both of Niigata University in Japan. Gonadatropins (GTHs) are a protein secreted from the pituitary, stimulating the gonads (ovaries and testes) to produce and release the sex steroid hormones which prompt their growth and maturation. GTHs are produced in response to hypothalamic gonadotropin-releasing hormone (GnRH), what Sower calls the “master molecule” for reproduction in vertebrates; its discovery remains the holy grail of understanding hagfish reproduction.
At 500 million years old, hagfish are the oldest living vertebrate, predating the dinosaurs. “They’re one of evolution’s great success stories,” says Sower, who has devoted the majority of her 30-year career researching hagfish and the similarly un-charismatic lamprey eels. “Here’s this animal with a backbone that we don’t know anything about.” They’re notoriously difficult to study, in part because their habitat is the ocean floor at 100 meters or more.
Yet their important evolutionary position makes hagfish worthy of scientific inquiry. “We look at the evolution of the hormones and receptors and say, ‘have they retrained characteristics of their ancestral forms, or are they more similar to higher vertebrates?’” says Sower. “They’re a key to understanding the evolution of later evolved vertebrates.”
Compounding the urgency of better understanding hagfish reproduction is their growing importance as a fishery in the Gulf of Maine. Despite their vicious nature and least appealing characteristic – the stress-induced secretion of mucous from up to 200 slime glands along their bodies – hagfish are prized, particularly in Asian markets. Their tough, soft skin is marketed as “eel” skin for wallets, belts and other items (“Because they’re not going to sell something that says ‘hagfish,’” says Sower, pulling out her own flawless 20-year-old eel skin wallet).
Fished in the Gulf of Maine since 1992, hagfish have been fished out of the waters off Korea and Japan and overfished on the U.S. West coast. They also play a significant role in nutrient cycling and ocean-floor clean-up, feeding primarily on dead and dying fish. Lacking knowledge on their reproductive functions – how, when and where they spawn – the hagfish could be fished to extinction, says Sower.
Sower, who directs the Center for Molecular and Comparative Endocrinology at UNH, has worked with Nozaki on hagfish reproduction since both scientists were postdoctoral researchers at the University of Washington in 1980. The two, along with Hiroshi Kawauchi of Kitasato University in Japan, have shared students and researchers through a formal collaboration that’s produced more than 30 papers. It’s also, notes Sower, produced many failures as they’ve labored to identify the hagfish GTH.
“Now we’re filling in the gaps of what we know,” she says.
To download a copy of the paper, go to http://www.pnas.org/content/107/36/15832.long.
This work was supported in part by a grant from the National Science Foundation. Sower’s ongoing work on hagfish gonadotropin has also been funded in part by the New Hampshire Agricultural Experiment Station.
The University of New Hampshire, founded in 1866, is a world-class public research university with the feel of a New England liberal arts college. A land, sea, and space-grant university, UNH is the state's flagship public institution, enrolling 12,200 undergraduate and 2,200 graduate students.
Beth Potier | Newswise Science News
Bolstering fat cells offers potential new leukemia treatment
17.10.2017 | McMaster University
Ocean atmosphere rife with microbes
17.10.2017 | King Abdullah University of Science & Technology (KAUST)
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
17.10.2017 | Life Sciences
17.10.2017 | Life Sciences
17.10.2017 | Earth Sciences