1. Introduction to model organisms
Model organisms are non human species which are commonly used to study biological processes. The use of these species is valid and is based off the 'common ancestor theory'. In short, the 'common ancestor theory' assumes that all current living organisms originated a single common ancestor. Small gradual changes in the gene are accumulated and varies as the species evolved separately.
Going back to the topic, here is a list of criteria that a suitable model species should ideally possess;
- Fast and short life cycles
- Easy to handle
- Easy to grow and maintain in laboratories
- Relatively well-known genome, with little junk DNA
- Easily manipulated (in terms of its genome)
- Conservation of biological processes
2. The significance of model organisms
Scientists have been working with various model species in the laboratory, for decades.
Most of what we know about living cells, its properties and biological processes have been discovered and studied using model organisms. Without the use of these organisms, much of the knowledge we have today may not be available, and many of the pharmaceuticals in the market may not be present.
Some notable model organisms include;
- Escherichia coli (bacterium): It has a small genome, and is easily manipulated. Used in the study of genes as well as proteins.
- Saccharomyces cerevisiae (yeast, aka baker's yeast): Has a similar cell cycle as that of humans, and is capable of carrying out similar modifications on synthesized proteins. Used in study of genes, cell biology and metabolism.
- Caenorhabditis elegans (roundworms): Has well defined developmental stages. Used to study development of cells.
- Drosophila melanogaster (fruit fly): Has similar genes as humans, some genes such as the homeo-box genes are conserved. Used to study development of an organism and the role of homeo-box genes in development.
- Mus musculus (the famous lab mouse): Has similar genetics as humans, which is about 90% similar. Used to study a wide variety of topics ranging from genetics, to evolution and behavior.
3. Future studies using model organisms
Many discoveries have been made, and many processes have been explained using the model organisms mentioned above. However, the use of these organisms continues to remain important as scientific research advances.
Fields and Johnston provided some possible areas of study that can be done using model organisms moving forward;
- Study and discover in-depth mechanisms and controls of various cell processes such as replication, transcription and translation.
- Study important medical issues such as metabolic diseases, neuro-degeneration (examples include Alzhemier's disease), cancer and even aging. The simple and intimately understood model organisms will hopefully provided a simpler system to study complex issues by breaking down these processes into its simpler components
- Develop new technologies. Many technologies widely used in research currently, were developed and tested through the manipulation of model species. Fields and Johnston believe that this trend will continue.