Biologists have uncovered the mystery of "dark matter" inside the cell
A group of biologists led by Yukiko Yamashita defined the role of satellite DNA, which does not encode proteins and refers to "junk" DNA (the "dark matter" of the genome). It turned out that the "useless" areas of deoxyribonucleic acid retained the chromosomes inside the nucleus of the cell. The article of scientists is published in the eLife journal. This is reported by the Science Alert.
The satellite DNA consists of repeating sequences of nucleotides, the sizes of which can vary from one nucleotide pair to several thousand. It is predominantly localized in centromeres-specific regions of chromosomes, in which sister chromatids are connected to each other (two identical identical chromatids linked together form a characteristic X-shaped form). Constitutive heterochromatin is formed from it - a region of compact packed DNA that does not contain genes.
The scientists removed the D1 protein from the cells of the common Drosophila melanogaster fruit fly. It is known that this compound binds to centromeric satellite DNA. It turned out that in the absence of D1, germ cells die in insects that participate in the formation of spermatozoa and oocytes. They formed micronucleus - fragments of the nucleus, which contain only part of the necessary for the survival of the genome.
Garbage DNA or "dark matter" of the genome is called a part of the genome, the role of which has not yet been established. Previously it was believed that DNA that does not encode proteins is useless to the body, but it is now known that it can perform structural and regulatory functions.