A pioneering journey through immunogenetics that revolutionized our understanding of fish disease resistance
Born and raised in IJmuiden, Netherlands, Stet developed an early fascination with marine life 1 .
Earned BSc and MSc in Medical Biology at University of Amsterdam with aquatic ecology minor 1 .
Completed Bachelor and Master of Science in Medical Biology at University of Amsterdam 1 .
British Council Fellowship at Aberdeen University's marine laboratory 1 .
Promoted to Associate Professor at Wageningen Agricultural University 1 .
Stet was "staunchly democratic and unpretentious," approaching scientific discussion with almost "boyish delight" when revealing his latest unpublished results and theories 1 .
Stet discovered that in bony fish, class I and class II MHC genes reside on different chromosomes and segregate independently, unlike in mammals where they're clustered together 1 .
| Component | Function | Significance in Fish Immunity |
|---|---|---|
| MHC Class I | Presents intracellular peptides to T-cells; found on nearly all cells | Defends against viruses and intracellular pathogens 7 |
| MHC Class II | Presents extracellular peptides to T-cells; found on specialized immune cells | Targets bacteria and extracellular pathogens |
| β2-microglobulin | Light chain that partners with MHC class I heavy chain | Essential for proper class I molecule folding and function 1 |
| Peptide-binding region | Most variable part of MHC molecules where pathogen fragments bind | Determines which pathogens can be recognized; extremely polymorphic |
Stet demonstrated that pathogen-mediated selection acted differently on various MHC components, with evidence for selection on class II genes but not class I genes in wild Atlantic salmon 1 .
Using common carp as his primary model, Stet's group applied molecular methods to discover and characterize carp MHC genes, with landmark papers published in 1993 1 .
In a 2008 experiment, Stet and colleagues discovered that Atlantic salmon eggs preferentially selected sperm from males genetically similar at the MHC class I locus, contradicting established theory 7 .
| Experimental Variable | Finding | Biological Significance |
|---|---|---|
| MHC Similarity Effect | Males won greater fertilization success with eggs from genetically similar females | Contrary to typical MHC-disassortative mating patterns 7 |
| Sperm Velocity | Covaried with MHC similarity effect | Confirmed known influence while revealing additional MHC effect 7 |
| Comparison to Other Species | Opposite pattern observed in sea urchins and ascidians | Suggests species-specific evolutionary pressures 7 |
| Tool/Method | Function | Stet's Application |
|---|---|---|
| PCR-RF-SSCP | Detects genetic variations by analyzing mobility of single-stranded DNA fragments | Screening large numbers of common carp for MHC class II B polymorphism |
| Molecular Cloning | Isolates and copies specific gene sequences | Identifying MHC genes in teleost species including carp, salmon, and trout 1 |
| Phage Display Technology | Identifies protein-protein interactions using viruses that display peptide sequences | Mapping peptide-binding specificity for vaccine development 4 |
| 2D Gel Electrophoresis | Separates proteins by charge and mass | Early attempts to identify salmon MHC molecules 1 |
| Database Curation | Organizes and standardizes genetic sequence information | Created and maintained the IPD-MHC database for fish 9 |
Stet helped optimize this technique to address the challenge of screening large numbers of individuals for MHC polymorphism without prohibitive sequencing costs .
Tragically, René Stet's prolific career was cut short when he passed away in 2007, just as he had embarked on an exciting new chapter as Professor of Zoology at Aberdeen University, where he occupied one of their prestigious Sixth Century Chairs 1 .
An avid birdwatcher, Stet approached science with the same wonder he brought to observing "thousands of migrating birds, particularly the honey buzzards, fly south out over the Baltic" 1 .
Stet shepherded fish immunogenetics from "dream to discovery" and from "collecting clones to field studies on fish in the wild," transforming our understanding of disease resistance in aquatic environments 1 .