Model organisms are organisms that can represent the research question is a simplified manner. Model organisms are typically well characterized with most of the biology already known. Model organisms are typically well conserved from humans, which makes it easy for information to be translated [1].
Common Model Organisms [2]
There is a wide variety of model organisms that exist and a variety of factors play into which organism is chosen. Certain fields of study favor the use of one organism over another. Below showcases several important and prominently studied model organisms that are used in the genetics field.
Mus Musculus (Mouse)
The mouse is a widely used model for studying human disease due to similar anatomical structure. Importantly, the mouse has been fully sequenced and has a wide variety of transgenic lines already developed to study mutations of interest.
Drosophila melanograster (Fly)
Fly's grow quickly and have shorter life spans than many common model organisms. Other benefits of using the fly in research include cheap maintenance. They only have four chromosomes and are commonly used in a wide array of research fields.
Danio rerio (Zebrafish)
The zebrafish is a transparent organism, making it easy to see many phenotypes obscured in other organisms. They are also easy to breed and maintain, while being cost effective. They also share similar organ structure compared to many model organisms.
Caenorhabditis elegans (Roundworm)
These are small, cheap, and easy to use organisms. They are commonly used underneath a microscope for easy visualization. While they do share Many similarities to humans, they typically have a genome that varies quite a bit from that of humans.
What Model Organism should be Used for ALK?
Cancer research is often focused on using murine models due to mice bearing many similarities in human anatomy and physiology. This is especially important for modeling lung based metastatic spread of disease. Mice can xenograft patient tumor cells or human lines directly to the mouse. There are currently several transgenic lines based on mutated ALK gene function. Cre-LoxP system can also be used to knockout the gene entirely. Mice are the model organism with the closest homolog and domain conservation to that of humans. Due to this, they are the model organism of this study.
Conclusions
Model organisms are incredibly important for studying human diseases and making an adequate model to represent the question being investigated. For studying ALK's relevance to cancer, mice are a particularly good organism to use. They have similar anatomy, a close homolog of ALK, and similar protein function.
References
[1] https://www.nature.com/scitable/definition/model-organism-model-genetic-organism-139/ [2] Simmons, D. (2008). The Use of Animal Models in Studying Genetic Disease: Transgenesis and Induced Mutation. Nature Education. Retrieved from www.nature.com/scitable/topicpage/the-use-of-animal-models-in-studying-855