ENCODE continues to work
Scientists have reported a new success in decoding the complete human genome
The international consortium ENCODE (Encyclopedia of DNA Elements), consisting of 500 biologists from many countries of the world, announced the completion of the third stage of a global project to compile an encyclopedia of functional DNA elements.
In 14 articles published in the journals Nature, Nature Methods and Nature Communications, the authors summarize the results of 17 years of work.
The human genome contains about 20 thousand genes encoding proteins, which account for only about 1.5 percent of the DNA of the human genome.
The ENCODE International Research Consortium, established in 2003 and conceived as a continuation of the Human Genome project, aims to compile a comprehensive catalog of functional elements of the human and mouse genome, including protein-coding genes, non-coding genes and regulatory elements.
All the results obtained during the implementation of the project are published in open databases. Thousands of researchers around the world have already used ENCODE data to identify genetic changes that affect the appearance of diseases such as cancer, cardiovascular diseases and many others.
"When the first draft of the human genome was completed, it immediately became clear that the primary sequence of the genome was a draft," the press release says. Laboratories in Cold Spring Harbor are the words of one of the consortium members, Professor Thomas Gingeras of the laboratory. "We knew where the genes were, but there wasn't enough knowledge about where the regulatory mechanisms and loci were located."
During the third phase of the project, the researchers conducted almost six thousand new experiments – 4,834 involving human samples and 1,158 on mice – and added more than 1,200,000 functional elements to the online registry – regions of non-coding DNA that regulate the transcription of genes covering 7.9 percent of the human genome and 3.4 percent of the mouse genome.
Part of the research is devoted to the study of the principles governing the operation of some of these functional elements.
For example, Michael Snyder from Stanford University Medical School in the USA and his colleagues investigated the interaction of chromatin – a complex of DNA and proteins – in 24 human cell types and found that differences in chromatin cycling between cell types can affect gene expression.
Thomas Gingeras' team studied the elements of the genome that instruct cells on how and when to transcribe DNA sequences into RNA. Scientists were able to identify and describe the molecular characteristics of five groups of human cells.
"Our work determines, based on gene expression, the main histological types by which human tissues are traditionally classified," says Roderic Guigó from the Center for Genomic Regulation, one of the authors of the study.
The consortium participants note that the elements controlling the functioning of genes are entirely encoded in the human genome and knowledge about their organization can serve as a starting point for studying human developmental disorders. However, despite the obvious progress, many elements that affect specific types or states of genes have yet to be identified.
"This encyclopedia is a living resource. It has a beginning, but in fact there is no end. Over time, it will only improve and grow," the authors write in the introductory article.
At the fourth stage of the study, ENCODE project participants plan to focus on new types of analyzed cells and tissues.
Portal "Eternal youth" http://vechnayamolodost.ru