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Top2. Use Case
It is important to understand the biological mechanisms determining how humans develop in order to better comprehend health issues such as cleft lips and cancer. Clearly, ethical and social considerations limit the experiments that can be performed upon humans. Accordingly, the mouse is often used as a model organism.
The developmental mouse is the mouse from the moment it is conceived until it is born. This period of time is commonly split into twenty-six distinct periods called Theiler Stages (TS). Each stage provides a snapshot of the growing mouse capturing its anatomy and how that anatomy differs from the previous stage.
DNA is the blueprint from which an individual is constructed. Genes are sub-sections of DNA that tell the body how to create proteins. Proteins are, amongst other functions, the building blocks that combine to form biological structures, e.g., the heart.
A specific gene will be used in the creation of some biological structures, but not others. A strongly expressed gene plays an important role in the development of a structure, whereas a weakly expressed gene has a lesser role, and a gene that is not expressed will not be involved. Determining where, and at what level, a gene is expressed is the purpose of a gene expression experiment.
There are a variety of technologies for assessing gene expression each with a slightly different focus. In this work, in situ hybridisation gene expression is used. These experiments are primarily concerned with determining precisely where a gene is expressed. Although information regarding the strength (or level) of expression is captured this is with far less granularity than the location information.
Experimental results can be published in traditional journals and/or online in resources like EMAGE (EMAGE, 2012). Figure 1 presents the result of one experiment, published in EMAGE, which is looking to discover where the gene Oxt2 is expressed in TS17 of the developmental mouse.
Figure 1. Result of EMAGE experiment EMAGE:1411. The gene is expressed in the midbrain (where the dark colour appears in the image). This image is best viewed in colour.