The genome is made up of DNA, a long, winding molecule that contains the instructions needed to build and maintain cells. For the instructions to be carried out, DNA must be read and transcribed – copied – into RNA. These gene readouts are called transcripts, and a transcriptome is a collection of all the gene readouts present in a cell. Transcription is a key process in the making of cellular proteins.
Researchers study the transcriptomes of cells as a way to gain insight into how genes function and what their expression means for a cell’s ability to do its job under normal conditions. Likewise, scientists can compare the transcriptome of a healthy cell to a diseased cell of the same type to better understand the changes taking place during the disease process.
In the Golden Retriever Lifetime Study Update 17.2, we introduced some basic genetic concepts. All cells have two types of genetic material: DNA and RNA, and these two molecules code for all the proteins made by a cell. An organism inherits its genetic code (made up of DNA and RNA) from both parents. Genes are simply portions of DNA that code for specific proteins.
The genetic material (DNA) contained in almost all of our cells is identical but different organs and tissues perform vastly different functions. What differentiates cells, and makes them able to perform specialized functions, lies in the way cells express the genes coded in their DNA. For example, the cells in the liver have a very different job and appearance than the cells that make up the skin yet they contain the same DNA. Which genes get transcribed in each type of tissue is what makes them different, and much of this difference resides in the proteins made in each cell.
When researchers study the transcriptome of a cell, they’re looking at a snapshot in time, and limited to studying only the genes that were turned on when that snapshot was taken. Because of this, timing of sample collection and having a comparison sample is important when studying transcriptomics.
Some of the samples requested from Golden Retriever Lifetime Study participants diagnosed with cancer may enable us to look at the transcriptome of tumors and nearby healthy tissue. In so doing, we will gain a better understanding of the changes the cancerous cells are undergoing. This information may provide clues about how the cancer process got started as well as provide potential targets for treatment.
In our next update, we’ll introduce another area of novel research: proteomics.