If you’re into yoga, you may be very familiar with “OM” or if you’re an electrician with “ohms”, but in science, we use “-ome” in a very different way. To start off, let’s give a silly example: the studentome (which I’m fairly sure does not actually exist). This would be the study of all “students” in a certain place. Maybe we’re interested in all of the students in a particular high school or college, and they can be categorized and better understood by looking at the distribution of their ages, their heights, their grade level, their clothing style, etc. The studentome would be different in an inner city school compared to a private Catholic school, and understanding these differences could help to improve or change aspects of the studentome in a certain place. The study of the studentome, would be called studentomics.
So what does this “-ome” mean? In Greek: “-ome” means “all” or “complete”. So whenever scientists put “-ome” at the end of a word, they are talking about all of something (like with the “studentome” all of the students), and in biology this usually is referring to all of something in an organism or a particular cell type. It’s not clear when scientists started using words ending in “-ome”, though the word biome was coined in the early 1900s. The modern usage likely started in the early 1990s as technologies, like computers and DNA sequencing, allowed scientists to study all of something in an organism with more ease. A derivative of the “-ome” is “-omics”, which is the study of all of something in an organism or a cell. This terminology is so common, there is even a wiki dedicated to “-omes” and “-omics” here.
Let’s explore some of the common “-omes” (you can find a more comprehensive list of scientific “-omes” here).
- Genome: The most famous “ome” is the genome. The genome refers to all of the DNA in an organism. In humans, this includes all 23 pairs of chromosomes (number 1-22 and the two sex chromosome, XX if you are female and XY if you are male). Scientists study the genome to understand the genetic blueprint of DNA because DNA codes for proteins, which are the functional machines that do everything in a cell.
- Transcriptome: For DNA to make a protein, the DNA needs to be “transcribed” in RNA first (read more details about this process here). All of the RNA in a cell is called a transcriptome. Scientists study the transcriptome because not all DNA is “turned on” to make proteins in every cell. This helps explain why certain cells look different (skin cells look different than eye cells) and have a different function (skin cells provide a barrier from the environment and specialized eye cells allow you to see).
- Proteome: And this brings us to the proteome, which is all of the proteins in a cell or organism. Since proteins are what’s actually doing stuff in a cells, by understanding what proteins are present in certain cells, scientists are able to better understand how those cells function. And in the case when there are problems, for example in cancer cells, it can help understand why there is a problem and possible ways to fix it.
- Interactome: Proteins interact with one another in a variety of ways. The interactome maps all of these interactions. The interactome is also different in different cell types because the proteins expressed are different in different cell types, so there are many interactomes
- Metabolome: Even though proteins are the machinery in a cell, there are lots of other small molecules and chemicals called metabolites. For example, glucose is a metabolite that is broken down to produce energy. All of the metabolites in an organism are called the Metabolome.
And there are hundreds more of these “-omes”! This “omeome” (originally and jokingly coined here) has even seeped into more popular culture. For example, the Facebookome, described as “The totality of facebook social network connections and nodes information such as people’s names, relationships, and multimedia contents.” Although it may seem to be an unnecessary wordy trend, these “-omes” and “-omics” are necessary for scientists to better understand health and disease.