EXTERNAL TRANSCRIBED SPACER Meaning and
Definition
-
The external transcribed spacer (ETS) is a region found in the ribosomal DNA (rDNA) of eukaryotic organisms that lies between the small-subunit (SSU) and large-subunit (LSU) rRNA coding sequences. It forms a non-coding region in the rDNA unit and is commonly utilized in molecular biology and phylogenetic studies.
The ETS is a stretch of DNA that is transcribed into RNA but is not involved in the synthesis of proteins. It exhibits a high degree of genetic variation among different species, making it an ideal target for genetic comparison and evolutionary analysis. The primary function of the ETS is believed to be the regulation of ribosomal RNA transcription and processing.
In molecular biology, the ETS is often employed as a genetic marker due to its faster rate of evolutionary change compared to protein-coding genes. It is utilized to investigate relationships between different organisms by comparing the sequences of their ETS regions. This information aids scientists in understanding the evolutionary history and relatedness between species.
The ETS serves as a valuable tool in phylogenetics, enabling the reconstruction of evolutionary relationships among organisms based on genetic data. By comparing the ETS sequences of different organisms, scientists can classify and classify organisms into various taxonomic groups and infer their evolutionary history.
Overall, the external transcribed spacer plays a crucial role in molecular biology and evolutionary studies by providing a non-coding region that exhibits significant genetic variation, allowing for genetic comparisons and phylogenetic analyses among different organisms.
