Hagfish slime, which has been described as the grossest super-material in existence, might be one of the most unique biomaterials known known to humankind — and UNH scientist and assistant professor David Plachetzki has received a grant from the National Science Foundation’s Integrative Organismal Systems program to study it.
The three-year project with Douglas Fudge at Chapman University will combine Plachetzki’s expertise in evolutionary genetics and phylogenetics with Fudge's expertise in cell biology, and the two researchers will share the ~$800,000 award, with roughly half going to UNH to support genomics research and half going to Chapman University to support cell biology research.
College of Life Sciences and Agriculture: Please describe the scope of research under the grant in nontechnical language.
Daivd Plachetzki: Hagfishes are a group of eel-shaped animals found in deep ocean habitats around the world. Hagfishes are notorious for their ability to thwart attacks by predators such as sharks by producing large volumes of gill-clogging slime within a fraction of a second after they are bitten. The slime is unique both in the speed with which it forms and because it contains thousands of silk-like fibers known as slime threads.
One aim of this project is to investigate how these 15-cm long fibers are produced within the specialized gland cells that secrete it. The second aim is to understand how the slime glands evolved and diversified. Hagfishes are an ancient group of about 78 described species, and the two species we have examined thus far have defensive slime that differs in significant ways.
This study offers the rare chance to try to figure out how something truly novel evolved. Did hagfishes invent new genes to produce these novel structures, or did they cobble together existing genetic material? These are fascinating questions that really excite people in my field of evolution and development.
In order to understand the evolutionary origins and diversification of hagfishes and their slime glands, we will collect anatomical and genetic data from many hagfish species from around the world. Our first collection expedition will take place this coming January at the Galapagos Islands, a hotspot for hagfish diversity.
COLSA: Why is this research important? Is there particular relevance for people in NH or our region?
Plachetzki: Hagfish slime threads have material properties that rival those of high performance spider silks, so understanding how they are produced within cells could thus provide valuable information for efforts to produce bio-inspired textiles.
Hagfish slime glands are also evolutionary novelties, which bear no obvious relationships to any other structures in vertebrates. Therefore, understanding how they evolved will lead to valuable insights on the evolutionary origins of complexity. In addition, the Gulf of Maine has a healthy hagfish fishery that serves markets around the world.
COLSA: Where does the work fit into a larger area of research?
Plachetzki: A fundamental question in biology is how do new traits evolve? Do new traits, like slime glands, require the evolution of new genes, or, are previously evolved genes simply combined together in new ways to produce a novel trait?
The slime gland study is helping to address this question as we have identified a host of genes involved in slime production that are not found in any other vertebrate genome. In addition, the study of the cell biology of slime production will exploit new methods in live microscopy.
COLSA: Will you be involving undergraduates in this research?
Plachetzki: Yes, we will be recruiting undergraduate researchers to help out with data production. In addition, the data produced in this study will be developed into educational modules for the undergraduate courses I teach at UNH, which include GEN 604 (Genetics), GEN 715 (Molecular Evolution), GEN 721 (Comparative Genomics) and MEFB 750 (Marine Ecological and Evolutionary Genomics).
COLSA: What excites you most about this research?
Plachetzki: Slime glands may sound sort of esoteric, I mean, who cares about slime glands, right? However, slime glands are one of the only true evolutionary novelties known from craniates (carniates are vertebrates and their close relatives). This study offers the rare chance to try to figure out how something truly novel evolved. Did hagfishes invent new genes to produce these novel structures, or did they cobble together existing genetic material? These are fascinating questions that really excite people in my field of evolution and development.
Also, hagfishes represent one of the earliest branching lineages in all of craniates. That means that the genomic resources that this study will yield for hagfish can, in the future, be applied to a host of other fascinating questions. I am particularly interested in how these data will help us to understand the evolutionary origins of the vertebrate senses and immunity.
Finally, hagfish are found all over the world, but mostly in the deep ocean. That means that our collection efforts will help our UNH team establish new connections and collaborations with researchers from all over the world.