What are model organisms?

• Model organisms are non-human species that are used in the laboratory to help scientists understand biological processes.
• They are usually organisms that are easy to maintain and breed in a laboratory setting.
• For example, they may have particularly robust embryos that are easily studied and manipulated in the lab, this is useful for scientists studying development.
• Or they may occupy a pivotal position in the evolutionary tree, this is useful for scientists studying evolution.

Why are model organisms useful in genetics research?

• Many model organisms can breed in large numbers.
• Some have a very short generation time, which is the time between being born and being able to reproduce, so several generations can be followed at once
• Mutants allow scientists to study certain characteristics or diseases. These are model organisms that have undergone a change or mutation in their DNA that may result in a change in a certain characteristic.
• Some model organisms have similar genes or similar-sized genomes to humans.
• Model organisms can be used to create highly detailed genetic maps:
  • Genetic maps are a visual representation of the location of different genes on a chromosome, a bit like a real map but one where the key landmarks are areas of interest in the genome.
  • For example, areas of DNA that differ between individuals in the same species (SNPs) or genes.

Examples of model organisms used to study genetics

• Yeast (Saccharomyces cerevisiae)
• Fruit fly (Drosophila melanogaster)
• Nematode worm (Caenorhabditis elegans)
• Western clawed frog (Xenopus tropicalis)
• Mouse (Mus musculus)
• Zebrafish (Danio rerio)