Satellite chromosome
Encyclopedia
The part of chromosome beyond the nuclear organiser is very short and appears like sphere (satellite ).The Satellite Chromosome is the chromosome
which has a bulge on the telomeric end and SAT stands for Sine Acid thymonucleinico(without thymonucliec acid or DNA )since the chromosome on staining show relative deficiency of DNA in the nuclear organiser region.There are at least 2 SAT chromosomes in each diploid nucleus.It plays a vital role in the formation of the nucleolous after division is completed.
It shows repetitive sequences of genes.
Besides centromere
, secondary constriction
can also be observed in some chromosomes, which if present in the distal region of the arm, would pinch off a small fragment called Satellite.
The satellite remains attached to the rest of the body of chromosome
s by a thread of chromatin
. The secondary constrictions are always constant in their positions and hence can be used as markers. The chromosomes having a satellite are marker chromosomes and are also called SAT chromosomes.these SAT chromosomes are helpful in transferring details to mRNA.
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
which has a bulge on the telomeric end and SAT stands for Sine Acid thymonucleinico(without thymonucliec acid or DNA )since the chromosome on staining show relative deficiency of DNA in the nuclear organiser region.There are at least 2 SAT chromosomes in each diploid nucleus.It plays a vital role in the formation of the nucleolous after division is completed.
It shows repetitive sequences of genes.
Besides centromere
Centromere
A centromere is a region of DNA typically found near the middle of a chromosome where two identical sister chromatids come closest in contact. It is involved in cell division as the point of mitotic spindle attachment...
, secondary constriction
Secondary constriction
Secondary constriction is seen at the chromosome in addition to primary constriction/centromere. Chromosome can bend only at the site of primary constriction during Anaphase. Secondary constrictions are useful in identifying a chromosome from a set...
can also be observed in some chromosomes, which if present in the distal region of the arm, would pinch off a small fragment called Satellite.
The satellite remains attached to the rest of the body of chromosome
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
s by a thread of chromatin
Chromatin
Chromatin is the combination of DNA and proteins that make up the contents of the nucleus of a cell. The primary functions of chromatin are; to package DNA into a smaller volume to fit in the cell, to strengthen the DNA to allow mitosis and meiosis and prevent DNA damage, and to control gene...
. The secondary constrictions are always constant in their positions and hence can be used as markers. The chromosomes having a satellite are marker chromosomes and are also called SAT chromosomes.these SAT chromosomes are helpful in transferring details to mRNA.