It all began a century ago, when genetics was not even a defined field of study, T H Morgan was busy with fruit flies (Drosophila melanogaster) in a 16 X 23 ft room in Columbia, working on chromosomal basis of inheritance. Morgan’s work established Drosophila as a good model organism for genetic studies. He won a Nobel Prize for medicine in 1933. Well this was just a start. More novel research came along when Drosophila entered the field of developmental biology. Works of Christiane Nüsslein-Volhard, Eric Wieschaus and Edward Lewis showed how genes play a role in embryogenesis. Their research paved way for understanding how multicellular animals develop from single genes. Further studies found closely related developmental genes in vertebrates, confirming an evolutionary link between fruit fly and human biology, after all 60% of genes are conserved between theses flies and us! They shared the Nobel Prize in Physiology or Medicine in the year 1995. Another remarkable study was made by Hoffmann and Lemaitre (Nobel Prize, 2011) on function Toll gene in innate immune response. Today Drosophila is greatly studied to answer neurodegeneration and aging processes.
While the “fly work” was prevailing, Sydney Brenner was striving hard to establish Caenorhabditis elegans (roundworm) as a model organism for developmental biology and neurobiology. He started his journey with worms in 1963. After a decade he finally brought C. elegans into limelight. He published an article “The Genetics of Caenorhabditis elegans” in 1974. His works along with John Sulston and Robert Horvitz made them Nobel laureates in 2002. They discovered genetic regulation of organ development and programmed cell death. This paved way for better studies of auto immune diseases. C. elegans was the first multicellular organism to get its genome sequenced. It showed 35% conservation of genes with humans. Being one of the simplest organisms with a nervous system, comprising only 302 neurons, and the pattern has been comprehensively mapped. This is the leading road to understand basic neuroscience and nerve related disorders, for instance, paralysis.
In the midst of flies and worms, some fishes were splashing from pet shops and home aquaria to swim their way in genetics’ world. Having the fancy name as Zebrafishes, Danio rerio became favourites of George Streisinger in 1970s. He wanted to use a simpler vertebrate model than mouse for his research, and being interested in tropical fishes, he chose Zebrafishes. The year 1981 was breakthrough in Zebrafish research, when Streisinger and his team successfully cloned Zebrafish. More boosts came to fish research when ‘Big Screen’ for mutants was carried out, and around 4000 mutants were discovered in 1990s. Interestingly these mutations were similar to wide variety of vertebrate development processes, including human congenital diseases. This led to insights into genetic basis of regulation of vertebrate development. Whole genome sequencing of Zebrafish was started in 2001 and it showed 70% similarity with humans and 84% of disease causing genes in humans have counterpart in Zebrafish. Being the youngest model in genetics research, it’s bread and butter for scientists across 600 laboratories in the world. Recent studies are been made to explore the regeneration capacity of caudal fins in Zebrafishes and better understanding of mechanism of bone formation to discover compounds of therapeutic potential.
So who’s the show’s topper now?