In this lesson, we’ll learn why different vertebrate model organisms are chosen in science. Zebrafish and mice don’t just make cute house pets, they are also great model organisms for genetic research.
Vertebrate Model Organisms
When trying to answer a question in genetic research, it’s important that you pick an appropriate model organism, or a non-human organism that is used to study a scientific process.
Model organisms can be any non-human organism, from a flowering plant to a chimpanzee. So how do you know which model organism is right for your research?Sometimes there’s more than one answer to that question. When picking a model organism, it’s important to consider many factors, including the cost of maintaining the organism, the generation time (or time it takes the organism to reproduce) and the ease of genetic manipulation (or the ability to change the genotype of an organism).
This is especially important in genetic research, where scientists want to understand specific mutations and the inheritance of these mutations.If a scientist wants to answer a question about photosynthesis, she will probably choose a plant as her model system. However, if a scientist wanted to study a basic scientific process, like DNA replication, then probably any living organism would be a good fit. Maybe for reasons of cost, she’d choose to use a really simple model organism like yeast.
But what if a scientist wants to study the development of an embryo, or the formation of the circulatory system or cancer? In these cases, a scientist will usually choose a model organism that shares this process with humans. In this lesson, we’ll discuss two model organisms, zebrafish and mice, that are vertebrate animals like us.
Zebrafish, or Danio rerio, are tiny little aquatic vertebrate animals that literally look like a cross between a zebra and a fish.
Their small size means you can keep a lot of them in one tank, allowing large numbers to be studied at once. The generation time of zebrafish is a few months, and many offspring are produced at once, making this a great model organism for genetic research. Their genomes are more closely related to humans than other non-vertebrate model organisms such as flies or worms.Zebrafish are becoming an increasingly popular model organism for studying vertebrate development, but it is still a relatively new model organism. As a fellow vertebrate, early stages of zebrafish embryo development are similar to human development. Zebrafish embryos are also transparent and large, which means it’s easy to see through these organisms and watch them develop into an adult fish. These organisms are popular for studying things like the development of blood clots and blood vessels.
Mice, or Mus musculus, are an extremely popular vertebrate model organism. This common house mouse is a mammal, like us, making it an ideal model organism for studying mammal development without studying humans. Mice are relatively small, cheap to maintain and go through generations relatively quickly – at least when compared to other mammals like us.Mice have long been used as a model organism for genetic research, and therefore many tools have been developed to manipulate their genomes. We’ll discuss the details of how this is done in other lessons, but for now, let’s appreciate that this rodent is a very dependable model organism for studying embryonic development and human disease.
Mice have all the organ systems that humans have, develop embryos in a uterus like humans do and can suffer from many of the same diseases as humans suffer from, such as obesity and cancer.
In this lesson, we’ve learned about two common vertebrate model organisms, or non-human organisms used in scientific research. Vertebrate model organisms, such as zebrafish and mice, are more expensive to maintain than most non-vertebrate model organisms. However, they are still cheaper than other larger organisms or using humans. The small size and quick generation time of zebrafish and mice, as well as the use of genetic manipulation, make them good model organisms for genetic research of development and human disease.
After finishing this lesson, students should recognize that scientist use model organisms for study and when studying things that reflect in humans, they must keep in mind the need to study vertebrate models like zebrafish and mice for a variety of reasons.