Week 1: No Fishy Business Here

Welcome to the city of molecular biology, traveler. 

I, Indeever, will be your trusty guide. Before, we embark on this journey together, I’ll need to give you a quick rundown of the laws of the land. If you have any questions, let minnow! 

Much like the wonderfully civilized society you’re from, every field of science has a set of laws. In Physics, we have the laws of Thermodynamics that dictate the flow of energy. In Chemistry, we have the Ideal Gas Laws that dictate the intrinsic properties of gases. 

Biology isn’t much different. The central dogma of molecular biology governs every aspect of every living organism. It explains how organisms evolve, grow, reproduce, and more. Here’s a diagram showing the “law” in action. 

To understand this “law”, it’s easier if we start at the end with proteins. 

Proteins: Proteins are complex molecules found that carry out cellular functions. They essentially perform the “work” of a cell. This could include signaling, catalyzing reactions, transport, mobility and more. Okay, that might be a little hard to understand, so let’s look at some examples in the human body. 

Insulin is a signaling protein produced by the cells in your pancreas tell the body your blood sugar is high. Keratin, a fibrous protein that gives structure to your body, makes up much of our hair, skin, and nails. Hemoglobin is a transport protein that helps move oxygen throughout your body. In short, without proteins, your body would not be able to perform the functions it needs to perform to keep you alive. 

Amino acids are the monomers (building blocks) of proteins. As seen in the diagram below, there are 20 such amino acids each of which are chemically distinct. 

But, how does a cell know what proteins it needs to make and which amino acids it needs to make that protein? It’s not like the cell has an instruction manual. Well, actually the cells in our body do in fact have an instruction manual called DNA. 

DNA: DNA which stands for Deoxyribonucleic Acid is the genetic material for all living things. Using combinations of 4 nucleotides, DNA “codes” for the instructions that tell the cell how to create proteins. From the table below, we can see structure of DNA representing the 4 nucleotides: Adenosine (A), Thymine (T), Guanine (G), & Cytosine (C).

But this begs a question. How exactly is the information stored in DNA turned into a protein? This is where RNA comes in. 

RNA: RNA acts as a sort of intermediary between DNA and proteins. The major differences between DNA and RNA is that RNA is single stranded, contains a Uracil nucleotide instead of a Thymine, and has a ribose sugar backbone instead of a deoxyribose backbone. Cells transcribe the DNA into RNA, and then translate the RNA into proteins. 

In this work, I aim to sequence the transcript-tome of the freshwater angelfish. The transcriptome is the collection of all the RNA molecules within the cells of an organism. Sequencing the transcriptome means that I aim to determine the nucleotides that comprise the collection of RNAs in the organism. This will help us determine what proteins are being expressed by the fish. Come back next time to learn more about my work!