“Junk” DNA, or “dark matter” of the genome, referred to as part of the genome, the role of which is still not installed.
Satellite DNA consists of repeating each other sequences of nucleotides, the size of which can vary from one base pair to several thousand. It is predominantly localized in the centromeres — specific regions of chromosomes, which are connected to each other chromatids (two interlocking identical chromatids form a characteristic X-shape). It is formed from constitutive heterochromatin is a compact area Packed DNA that contains no genes.
Scientists have removed the D1 protein from the cells of the common fruit fly Drosophila melanogaster. It is known that this compound binds to centromeric satellite DNA. It turned out that in the absence of D1 in insects die, the germ cells involved in the formation of sperm and egg. They formed micronuclei — fragments of the nucleus, which contains only the part necessary for the survival of the genome.
“Junk” DNA, or “dark matter” of the genome, referred to as part of the genome, the role of which is still not installed. Previously it was thought that DNA that does not encode proteins, useless to the body, however it is now known that it can perform structural and regulatory functions.