Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


UNH researcher helps identify key reproductive hormone in oldest vertebrate

Looking at a hagfish – an eyeless, snot-covered, worm-like scavenger of the deep –the last thing that comes to mind is sex. Yet the reproductive functioning of these ancient vertebrates is such an enduring enigma that a gold medal was once offered to anyone who could elucidate it.

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

This work was supported in part by a grant from the National Science Foundation.

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.

Photographs available to download:

Caption: University of New Hampshire professor of biochemistry Stacia Sower and colleagues have identified the first reproductive hormone of the hagfish, the world's oldest living vertebrate. Credit: Courtesy of Stacia Sower.

Caption: UNH professor Stacia Sower and researchers in her lab collect hagfish from the Gulf of Maine for study. Credit: Courtesy of Stacia Sower.

Caption: UNH professor Stacia Sower (in orange) and researchers in her lab collect hagfish from the Gulf of Maine for study. Credit: Courtesy of Stacia Sower.

Beth Potier | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>