what is satelite dna , write its types, importance and functions
plz don't spam
Answers
Explanation:
Satellite DNA is mainly present in heterochromatin or the tightly packed regions of chromosomes in centromeres, telomeres, and sometimes even in the euchromatin region (active region of the genome). Although conventionally satellite DNA has been known to be ‘non-coding’ (i.e. it does not encode protein), recent evidence suggests that some of the satellite DNA does undergo transcription. 6
19
What is Satellite DNA?
Dr. Surat P, Ph.D.
By Dr. Surat P, Ph.D.
Reviewed by Kate Anderton,
Satellite DNA consists of arrays of tandemly repeating sequences that are widely present (>30%) in the genome.
Satellite DNA is mainly present in heterochromatin or the tightly packed regions of chromosomes in centromeres, telomeres, and sometimes even in the euchromatin region (active region of the genome). Although conventionally satellite DNA has been known to be ‘non-coding’ (i.e. it does not encode protein), recent evidence suggests that some of the satellite DNA does undergo transcription.
Satellite DNA structure
Satellite DNA consists of arrays of tandem repeats or repeats arranged side-by-side. These repeats can be as small as 1−2 bp long or as long as 10−60 bps long. The short tandem repeats (1-2 bp long) are called microsatellite or simple sequence repeats (SSRs), while the longer tandem repeats (10-60bp long) are called minisatellites or variable number tandem repeats (VNTRs).
The regions in between two simple sequence repeats or microsatellite are termed as ‘inter simple sequence repeats’ or ISSRs. Due to the presence of large number of repeats, the mutation rate is high in satellite DNA. It is speculated that as most of these sequences do not code for proteins, the detrimental consequences of high mutation rate is low. Thus, there is no selection pressure against it.