Genomics Glossary for RNA Sequencing Up Close

base pairs (bp)

Paired nucleotides that make up DNA and RNA. Following specific hydrogen-bonding patterns, DNA has adenine(A)-thymine(T) and guanine(G)-cytosine(C) base pairings. Similarly, RNA has adenine-uracil(U) and guanine-cytosine base pairings

bioinformaticians

scientists with multidisciplinary training in computer science and biology who are equipped to answer important biological questions based on analyzing and interpreting huge biological-based datasets

database

an organized collection of information that can be accessed, managed, and updated

DNA Sequencing

“Reading” the DNA molecule to determine the sequence of the letters

exome

a collection of all the protein-coding sequences (exons) found in the genome. This is the part of the human genome we understand best, but the exome only makes up about 2% of the entire genome.

exons

the pieces of RNA that we keep in the final messenger RNA molecule to code for proteins

flow cell

a special glass plate that is a little larger than a microscope slide, which is used to attach DNA or cDNA (made from RNA) samples to sequence them in next-generation sequencing machines

gene

a unit of DNA that controls specific traits

gene expression

the process by which instructions in our DNA are converted into functional products, such as proteins (read more about the basics of gene expression)

gene quantification

counting the number of reads we have assigned to each gene

genome

all the DNA in an organism

genomics

the study of a large number of genes and their interactions and/or of entire genomes (all of the DNA in an organism) to learn what kind of information is coded in these DNA sequences and how the DNA instructions are carried out

hip dysplasia

a hip joint structural problem

hypothesis

an educated guess that can be tested

introns

the pieces of RNA that are removed from final messenger RNAs (these segments are not used to code for proteins)

multimappers

Sequencing reads that align to multiple locations

mutation

alterations in the DNA

nucleotides

the basic structural units of nucleic acids such as DNA and RNA. They are made up of a nucleoside coupled to a phosphate group

paired-end reads

two reads that were sequenced from opposing ends of the same molecule. See paired-end sequencing.

paired-end sequencing

a type of sequencing that obtains reads starting from opposing ends of the same molecule. The reads are output as paired-end reads.

primer

short nucleotide sequences that serve as a starting point for DNA synthesis. They are required for DNA replication because DNA polymerase can only add nucleotides to an existing DNA strand.

read alignment, read mapping

The entire process of taking sequencing reads and assigning them to specific locations in the genome

ribonucleic acid (RNA)

a nucleic acid molecule that is implicated in various biological roles, including coding, decoding, regulation, and expression of genes.

RNA sequencing (RNA-seq)

a technique that reveals the presence and quantity of RNA in a biological sample at a given moment in time.

RNA splicing

The process of editing messenger RNA during transcription through removal of introns. Exons are joined together through a process called ligation.

sequencing

The process of determining the order of nucleotides that makes up DNA or RNA

sequencing reads

a list of short nucleotide sequences (100-200 letters, or base pairs (bp)

single-end reads

reads that were sequenced from only one end of the molecule (as opposed to paired-end reads)

spliceforms

different variations of messenger RNA that are produced by the same gene; which specific spliceforms and how much of each type are produced from a gene can change what is translated into proteins; having "alternative spliceforms" is a way a single gene can respond to different biological situations by producing different products using the same string of DNA sequence.

spliceosome

a biological machine made up of RNA and protein complexes which function to remove introns from a trascribed pre-mRNA and then ligate the exons together

string

a sequence of one or more letters

transcription

the process in which information in a strand of DNA is decoded into a messenger RNA molecule