A human is a complicated organism, and it is considered unethical to do many kinds of experiments on human subjects. For these reasons, biologists often use simpler “model” organisms that are easy to keep and manipulate in the laboratory. Despite ob
Model organisms and conservation of function: A human is a complicated organism, and it is considered unethical to do many kinds of experiments on human subjects. For these reasons, biologists often use simpler “model” organisms that are easy to keep and manipulate in the laboratory. Despite obvious differences, model organisms share with humans many key biochemical and physiological functions that have been conserved (maintained) by evolution. Organisms share similar genes because they have inherited them from common ancestors. Even humans and yeast share many genes! The complete DNA sequence, the genome, is carried in the nucleus of every somatic cell (cells that are not sex-linked). In genes, three-letter groups of DNA sequences are converted to amino acids, which join together to form a protein. Amino acids can be represented using either 1 or 3 letters. If we look at a portion of the amino acids derived from the Ras gene, we can see similarities between humans and yeast. Let’s take a closer look at the ras gene in humans and yeast. The amino acids are labeled only in the first row; the remaining residues are represented by dashes. There are also highly variable regions in proteins. Some of these… …ten! Because many sequences are common across species, it is possible to place substitute human genes in model organisms without affecting protein function. This ability allows us to study how humans may respond in many experimental conditions.
model organisms, model systems, model, human, chimp, chimpanzee, evolution, conservation, yeast, fly, drosophila, fruit fly, protein, amino acid, nucleotide
- ID: 555
- Source: DNALC.G2C
Model organisms such as yeast, bacteria, the mouse and the fruit fly are used by researchers to study biological systems. The genomes of these organisms have been mapped and sequenced.
Model organisms share with humans many key biochemical and physiological functions that have been conserved (maintained) by evolution.
Some of the plants, animals, and microorganisms used by researchers as "model" biological systems.
Doctor Josh Dubnau explains that model systems are particular species of animals that substitute for humans or other animals. For genetic and historic reasons, the fruit fly is a commonly used model.
Professor David Van Vactor discusses the properties that make the fruit fly (drosophila) a powerful model system.
The fruit fly is easy to maintain, has large numbers of offspring, and grows quickly. The fruit fly shares with humans a number of so-called “master,” or homeotic, genes.
Professor Ron Davis discusses the attributes that make the fruit fly a good model for studying memory in humans.
Students work through a series of experiments that investigate the use of model organisms in the search for a better understanding of the genes that influence memory formation.
Professor David Van Vactor provides a simple explanation for why researchers work with model systems (model organisms).
Find a cystic fibrosis protein function using bioinformatics to study homologs in model organisms.