Gene transcription is the process of creating an RNA copy of a DNA sequence. The term is spelled as "dʒiːn trænsˈkrɪpʃən" in IPA phonetic transcription. The "dʒiːn" part is pronounced with a 'j' sound, followed by a long 'e' vowel sound. "Træns" is pronounced with a soft 's' sound and a short 'a' vowel sound. "Krɪpʃən" uses a hard 'k' sound, followed by a short 'i' vowel sound, and a 'sh' sound. Pronouncing the word correctly is important in the field of genetics and molecular biology.
Gene transcription is a fundamental biological process involved in the synthesis of RNA molecules from DNA templates. It is the first step of gene expression where the genetic information stored in the DNA molecule is converted into a transient RNA molecule, particularly messenger RNA (mRNA), which carries the instructions necessary for protein synthesis.
During gene transcription, the DNA double helix is unwound by enzymes called RNA polymerases, exposing the nucleotide sequence of a particular gene. The RNA polymerase enzyme then binds to specific promoter sequences located near the beginning of the gene. This binding initiates the transcribing process as the enzyme moves along the DNA molecule in a process called elongation.
As the RNA polymerase moves along the DNA template, it reads the DNA sequence and synthesizes a complementary RNA strand by pairing RNA nucleotides with specific DNA bases. The process continues until the RNA polymerase reaches a termination signal, at which point it dissociates from the DNA template and releases the newly formed RNA molecule.
Gene transcription is a highly regulated process that controls gene expression in response to various environmental, developmental, and physiological signals. It allows cells to selectively transcribe specific genes needed for their biological functions, thereby determining the production and regulation of proteins. These proteins are essential for various cellular processes such as metabolism, cell signaling, and structural functions, ultimately influencing the phenotype and behavior of living organisms.
The word "transcription" comes from the Latin word "transcribere", which is a combination of "trans" meaning "across" or "over", and "scribere" meaning "to write". In a general sense, "transcription" refers to the act of transcribing or copying something from one form to another.
The term "gene transcription" specifically relates to the process of copying genetic information from DNA to RNA. In this context, "gene" refers to a segment of DNA that encodes a specific functional product, such as a protein or an RNA molecule.
The concept of transcription was initially proposed by the early molecular biologists François Jacob and Jacques Monod in the 1960s. They defined and elucidated the process of gene transcription during protein synthesis.