Evolution and humans; how many genes? (Evolution)

by David Turell , Saturday, September 01, 2018, 21:57 (2273 days ago) @ David Turell

Another study that suggests less so-called human genes code for protein and may be pseudogenes:

https://medicalxpress.com/news/2018-08-team-reveals-human-genome-percent.html

"A new study led by the Spanish National Cancer Research Centre (CNIO) reveals that up to 20 percent of genes classified as coding (those that produce the proteins that are the building blocks of all living things) may not be coding after all because they have characteristics that are typical of non-coding or pseudogenes (obsolete coding genes).

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"The researchers analyzed the genes cataloged as protein coding in the main reference human proteomes. The detailed comparison of the reference proteomes from GENCODE/Ensembl, RefSeq and UniProtKB found 22,210 coding genes, but only 19,446 of these genes were present in all 3 annotations.

"When they analyzed the 2,764 genes that were present in only one or two of these reference annotations, they were surprised to discover that experimental evidence and manual annotations suggested that almost all of these genes were more likely to be non-coding genes or pseudogenes. In fact, these genes, together with another 1,470 coding genes that are present in the three reference catalogs, were not evolving like typical protein coding genes. The conclusion of the study is that most of these 4,234 genes probably do not code for proteins.

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"The work once again highlights doubts about the number of real genes present in human cells 15 years after the sequencing the human genome. Although the most recent data indicates that the number of genes encoding human proteins could exceed 20,000, Federico Abascal, of the Wellcome Trust Sanger Institute in the United Kingdom and first author of the work, says, "Our evidence suggests that humans may only have 19,000 coding genes, but we still do not know which 19,000 genes are."

"For his part, David Juan, of the Pompeu Fabra University and participant in the study, reiterates the importance of these results: "Surprisingly, some of these unusual genes have been well studied and have more than 100 scientific publications based on the assumption that the gene produces a protein. "

"This study suggests that there is still a large amount of uncertainty, since the final number of coding genes could 2,000 more or 2,000 fewer than it is now. The human proteome still requires much work, especially given its importance to the medical community."

Comment: The less genes that make a complex human means the human genome has many hidden layers of complexity to explain how the low number results in such complexity. I can remember when DNA was first studied, 'experts' predicted we would have 100 genes.