Number of genes: chronicle of ignorance

2002/02/18 Roa Zubia, Guillermo - Elhuyar Zientzia

• Biokimika
• Genetika

How many proteins does the human genome encode? Before starting the serial sequencing carried out in its day, it was commented that it could be around 100,000. This information would cover thousands of books written on paper. However, biochemicals found an "overinformation", that is, that much of the genome did not encode proteins. The part of the genome that encodes a protein is called gene. So, how many genes does the human genome have?

When the draft sequence of the entire human genome was completed last year, one of the remarkable data was that there are many fewer genes than the experts thought. It was estimated that there could be about 30,000 in all the media, hence hundreds of evaluations were drawn up due to the comparison between human genes and the Drosophila melanogaster fly, among others. They also commented that a gene can store information from more than one protein.

To obtain these results, computer programs for the detection of gene sequences were used. Now, the team of the American biochemist Victor Velculescu has used a new strategy for gene counting, with different results. It has been tried to predict the number of genes through isolated RNA molecules and it has been proven that it can be around 70,000.

This amount is very variable from research to research. Therefore, until a thorough investigation of proteome ends, we must accept our ignorance.