Hagfish Hormone Discovered

An international team of scientists has identified the first reproductive hormone in the hagfish, a primitive jawless fish. 

This research sheds new light on evolutionary divergent processes involving reproduction and growth. The finding provides critical evidence for the existence of a pituitary-gonadal system in the earliest divergent vertebrate.

Just as their name suggests, hagfish are unlikely to win any beauty contests in the animal kingdom. However, what they lack in aesthetics they make up for in evolutionary simplicity. Lacking both jaws and vertebrae, hagfish are among the most primitive chordates known, living or extinct. They have long been the enigma of vertebrate evolution, not only because of their evolutionary position but because there are many questions about fundamental hagfish processes such as maturation and reproduction.

Stacia Sower and her research team at New Hampshire University are working to elucidate some of these lesser-known processes, using techniques involving neuroendocrinology, hormonal genomics and proteomics. The hormone Sower and her team discovered acts as a gonadotropic hormone, stimulating reproductive function. In response to a hypothalamic hormone, the pituitary secretes gonadotropins, which stimulate the gonads, inducing the synthesis and release of sex steroid hormones, which in turn elicit growth and maturation of the gonads.