Researchers CNIOA update number of human genes to 19,000 -
Over 99% of the genes encoding human proteins have an earlier origin for primates by over 50 million years. The study challenges the genomic annotations of many different species
how nutrients are metabolized and how neurons communicate in the brain are some of the messages encoded by the 3 billion letters that make up the human genome . Detection and characterization of genes in this mass of information is a complex task that has been an ongoing source of debate since the first systematic attempt by the human genome project there are more than ten years.
A study by Alfonso Valencia, vice-director of basic research at the National Spanish Research on Cancer (CNIO) and Head of Structural Computational Biology Group, and Michael Tress, a researcher at Group updates the number of human genes-those that can generate proteins - 19,000; Less than 1700 genes in the annotation latest and significantly lower than the initial estimates of 100,000 genes. The work, published in the journal Human Molecular Genetics , concludes that almost all of these genes have ancestors before the appearance of primates there are 50 million years.
"The human genome shrinks," is how Valencia describes the continuous corrections to the numbers of genes encoding proteins in the human genome over the years which has resulted in 19,000 human genes described in this book. "The coding portion of the genome [which produces proteins] is constantly moving," he adds. " Nobody could imagine a few years ago that such a small number of genes could make something so complex "
The scientists began by proteomics experiments; Proteomics is the most powerful tool for detecting protein molecules. in order to determine human protein card researchers have incorporated data from seven large scale mass spectrometry studies, more than 50 human tissues, "to verify which genes not really produce proteins "says Valencia.
fewer than ten new GENES MICE AND MEN SEPARATE
results highlighted a little more than 12,000 proteins and researchers mapped these proteins in the corresponding regions of genome. They analyzed thousands of genes that were annotated in the human genome but not in proteomic analysis and concluded: "1700 genes that are supposed to generate almost certainly proteins for various reasons, either because they are also not all protein coding features, or because the preservation of their reading frames can not stand the protein coding capacity, "said Tress.
a hypothesis derived from the study is that over 0% of human genes produce proteins that come from metazoans or multicellular animal kingdom hundreds of millions of years ago, the figure is over 99% for genes whose origin predates the emergence of primates there are 50 million years.
"Our figures indicate that the differences between humans and primates in genes and proteins are very small," say the researchers. David Juan, author and researcher in the laboratory of Valencia, says that "the number of new genes that separate humans from mice [those genes that have evolved since the split from primates] may even be less than ten." This contrasts with the more than 500 human genes origination from primates that can be found in the current annotation. The researchers conclude:
"The physiological and developmental differences between primates may be caused by gene regulation rather than by differences in the basic functions of the proteins in question." do more with less
sources of human complexity lie more in how genes are used rather than the number of genes in thousands of chemical changes that occur in proteins or control of the production of these proteins by non-coding regions of the genome, which represent 0% of the entire genome and have been described in the recent conclusions of the international ENCODE project, a project in which the Valencian team participates.
work brings the number of the closest human genes with other species such as nematodes Caenorhabditis elegans worms that are just 1mm long, but apparently less complex than humans. But Valencia prefers not to make comparisons: "The human genome is the best annotated, but we still believe that 1700 genes can be re-annotated Our work suggests that we will have to redo the calculations for all genomes, not only the human genome. . "
the search results are part of Gencode, a consortium that is integrated in the ENCODE project and formed by research groups around the world, including the Valencia team, whose task is to provide an annotation all gene-based elements in the human genome.
"Our data are discussed by Gencode for incorporation into new annotations. When this happens, it will redefine the entire human genome mapping, and how it is used in macro projects such as those for cancer genome analysis, "said Valencia.
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