The decoding of the human genome was made a long time ago, but the exact number of genes was not known. And just recently, scientists decided to find out how many genes our genome contains. And the result was extremely surprising.
It is worth noting that the counting of the number of genes has been done since 1990 within the framework of the Human Genome Project (HGP). The project ended 17 years ago and according to the data received, the most relevant database today contains information on 22298 protein-coding genes and their 34214 transcripts.
It would seem, why did the scientists need to double-check the data that had been painstakingly collected for more than 10 years? The DNA and RNA sequencing technology is to blame for everything. The fact is that, according to some ideas, many experts consider the genome and nucleotide sequence encoding RNA, on which no protein is synthesized, but which itself is involved in transformations. Thus, they could "fall out" when counting, which means that the number of genes in the end may turn out to be much larger than expected. Last 2017, a team of researchers led by Steven Salzberg, a statistical biologist at the Johns Hopkins Institute, began work to recheck the composition of the human genome.
For their work, the experts analyzed about 10,000 experiments on RNA sequencing from 31 human tissue samples. It turned out that the updated database contains 43,162 genes, of which 21306 encode proteins, and the rest do not encode anything. At the same time, almost 500 new genes and 30 million new transcript variants were added to the catalog. As stated by Mr. Salzberg himself, Vladimir Kuznetsov
