Illuminate DNA "dark matter"!

These DNAs occupy 98% of the human genome, but they cannot encode proteins and were once considered "junk".

At the beginning of the 21st century, mankind's self-awareness has taken a big step forward because of a large-scale international cooperation project

An important reason is that less than 2% of the human genome can encode proteins, which directly guide a series of life activities; while more than 98% of the genome is located in non-coding regions and cannot participate in protein encoding

Only in recent years have scientists gradually realized that although these DNA "dark matter" are not directly involved in the coding of proteins, they are closely related to the expression and regulation of genes, as well as the mechanism of a series of diseases

In non-coding regions, cis-regulatory elements composed of promoters, enhancers, regulatory sequences and inducible elements are extremely important

However, the lack of a map of cis-acting elements in the human genome has become a major obstacle to our understanding of mutations in noncoding regions

An international collaboration called the Encyclopedia of DNA Elements, or ENCODE for short, is trying to bring this "dark matter" to light

In recent years, the ENCODE project has identified hundreds of thousands of cis-acting elements in the human and mouse genomes, respectively

In the latest study published in Cell, Professor Ren Bing's team achieved this goal

Normally, histones in chromatin are tightly wound around DNA, so that DNA nearly 2 meters long can be wrapped in a nucleus that is 10 micrometers in diameter

In this study, Prof.

▲Data from adults and fetuses build a huge map of cis-acting elements (Image source: Reference [1])

They then integrated the data with data from fetuses in previous studies

In addition, the study identified cell types associated with 240 disease or polygenic traits through genome-wide association analysis and identified pathogenic risk of mutations in cis-acting elements

It is worth mentioning that in October this year, Professor Ren Bing's team just published a paper in the journal "Nature", mapping the cis-acting elements in the mouse brain, and revealing the relationship between these cis-acting elements and the human genome.

Note: The original text has been deleted

References:

[1] Kai Zhang et al.

[2] Illuminating dark matter in human DNA.

[3] Li, YE et al.
, An atlas of gene regulatory elements in adult mouse cerebrum.
Nature (2021).
https://doi.
org/10.
1038/s41586-021-03604-1