Introduction
The Caenorhabditis elegans (Korean: 예쁜꼬마선충) is a free-living roundworm that is transparent and 1 mm in length. It lives in temperate soil, and it’s scientific classification of kingdom-phylum-class-order-family-species is Animalia-Nematoda-Chromadorea-Rhabditda-Rhabditidae-Caenorhabditis-C. elegans, respectively.
Importance in Research
The reason the Caenorhabditis elegans is used so widely in research can be divided in to two main reasons. First and most importantly, it is one of the simplest organisms with a nervous system. Unlike many other complex bodies, the neurons do not fire action potentials, and do not express any voltage-gated ion channels. The whole system comprises of 302 neurons, which have been comprehensively mapped. The resulting connectome has been shown to be a small-word network. The relatively simple neural network is therefore fit to study several behaviors of animals such as learning, memory, mating behavior, chemotaxis, and thermotaxis. Recently, the model has been used as a model organism for studying molecular mechanisms in metabolic diseases. Furthermore, the total amount of somatic cells of a Caenorhabditis elegans is around 1000. Due to these features, research has been actively conducted; there are large amounts of research data about the gene knockout, mutagenesis, RNA interference, and transgenesis.
Secondly, the organism is cheap and easy to incubate. The life span of a Caenorhabditis elegans is around three weeks, and they can be incubated in an Agar plate, or an E. coli incubating environment. This drastically reduces the cost of research based of the organism. Also, the specimen can be frozen for further study, so there is no need to incubate more to study a function in detail. The organism gives birth to around 300 young Caenorhabditis elegans, so there is no need to worry about a shortage, either.
Research Fields
Some fields that the Caenorhabditis elegans are used to study are the following:
Studying Apoptosis
Because the Caenorhabditis elegans have less somatic cells compared to other multicellular eukaryotic organisms, they are widely used as a model organism for documenting how each cell differentiates from their birth to death. H. Robert Horvitz studied the 1090 cells that make up the organism to find that 131 cells have undergone programmed cell death, leading to the death of the animal itself. Furthermore, genes similar to those that took part in the Caenorhabditis elegans’s cell death (ced-3, ced-4, ced-9) have been found in humans. Overall, the research about Caenorhabditis elegans has improved our understanding of apoptosis on a molecular level, and has led us to believe that apoptosis is related to many diseases such as cancer.
Study of Diseases
In most cases, diseases common to both humans and Caenorhabditis elegans have no direct relationship. However, it is easy to get quick and exact results regarding a certain disease, whilst maintaining a large amount of control. Also, by comparing the genes of the Caenorhabditis elegans and humans, researchers have found that they share 60%~80% of their genes. This signifies that that research about these microorganisms can easily lead to research in the human field. Not only that, the fact that a molecule-level analysis is possible makes it extremely well suited for research for cancers related to the nervous system, Alzheimer’s disease, Huntington’s disease, neurodegration diseases, and depression.
Study of Aging
Scientists have found that the life span of Caenorhabditis elegans can be elongated to nearly two times their original length if the gene age-1 is expressed. Their results show that the gene increases amounts of superoxide dismultase(SOD) and catalase within the body, which increases the ability to resist stress from oxidation. Another way in which age-1 decreases aging speed is by protecting the degradation of the genes of mitochondria.