New Blog on the Block
14/07/10 15:30 Filed in: GenomeWeb Daily Scan
Submitted by S. Pelech - Kinexus on Mon, 09/10/2012 - 05:10
In Luke Jostin's blog article on the importance of sequencing in personal genomes, he does a nice job of pointing out some of the millions of variations in nucleotide base changes, insertions and deletions in individual human genomes. It will take many decades to sort out which of these are truly meaningful and useful. Less than 3% of the human genome actually encodes proteins and other recognizable RNA elements such as tRNA, rRNA and microRNA. Over 97% of the genome is probably filler or "junk" DNA. This is pretty apparent when one considers the number of nucleotides in humans compared to other species. Humans have about 2.9 billion base pairs (bp) in their genome, whereas the lungfish has 139 billion bp, the flower Fritillaria assyriaca has 124.9 billion bp, and the crested newt has 18.9 billion bp. Even amongst insects the total number of nucleotides in their genomes can vary markedly. For example, the fruit fly Drosophila melanogaster has 0.165 billion bp, whereas the mountain grasshopper mountain grasshopper Podisma pedestris has 14 billion bp. The vast majority of genomic differences in people will be found in these non-coding regions of their genomes.
The excitement surrounding the value of the sequencing of personal genomes is extremely misplaced in view of the very limited understanding that we presently possess about the ~23,000 genes in the human genome and the proteins that they encode. The phenotype of individuals cannot be simply predicted from the sequences of these genes or even the levels of the mRNA transcripts from these genes. Post-translational modification of proteins plays an equally important role. Gene expression is strongly influenced by the environment, and the traits of humans and other organisms is manifested ultimately at the protein and metabolome levels. The balance between healthy and pathological states is the outcome of extremely complex regulatory systems that operate at the molecular, cellular and organ levels, often with immense redundancy and feedback controls, which permit organisms to survive and operate in changing environments.
The current euphoria about genome sequencing, including eventually the genomes of hundreds of thousands of people over the next decade will lead to a major diversion of funding and research into relatively non-productive directions. This will probably result in even less attention devoted to understanding the roles and interactions of proteins. Regretfully, without this knowledge, it will be impossible to interpret the results of genome sequencing studies. Government and charitable organizations that fund biomedical research should be doing a much better job in coordination of genomics- and proteomics-based studies.
Link to the original blog post.
In Luke Jostin's blog article on the importance of sequencing in personal genomes, he does a nice job of pointing out some of the millions of variations in nucleotide base changes, insertions and deletions in individual human genomes. It will take many decades to sort out which of these are truly meaningful and useful. Less than 3% of the human genome actually encodes proteins and other recognizable RNA elements such as tRNA, rRNA and microRNA. Over 97% of the genome is probably filler or "junk" DNA. This is pretty apparent when one considers the number of nucleotides in humans compared to other species. Humans have about 2.9 billion base pairs (bp) in their genome, whereas the lungfish has 139 billion bp, the flower Fritillaria assyriaca has 124.9 billion bp, and the crested newt has 18.9 billion bp. Even amongst insects the total number of nucleotides in their genomes can vary markedly. For example, the fruit fly Drosophila melanogaster has 0.165 billion bp, whereas the mountain grasshopper mountain grasshopper Podisma pedestris has 14 billion bp. The vast majority of genomic differences in people will be found in these non-coding regions of their genomes.
The excitement surrounding the value of the sequencing of personal genomes is extremely misplaced in view of the very limited understanding that we presently possess about the ~23,000 genes in the human genome and the proteins that they encode. The phenotype of individuals cannot be simply predicted from the sequences of these genes or even the levels of the mRNA transcripts from these genes. Post-translational modification of proteins plays an equally important role. Gene expression is strongly influenced by the environment, and the traits of humans and other organisms is manifested ultimately at the protein and metabolome levels. The balance between healthy and pathological states is the outcome of extremely complex regulatory systems that operate at the molecular, cellular and organ levels, often with immense redundancy and feedback controls, which permit organisms to survive and operate in changing environments.
The current euphoria about genome sequencing, including eventually the genomes of hundreds of thousands of people over the next decade will lead to a major diversion of funding and research into relatively non-productive directions. This will probably result in even less attention devoted to understanding the roles and interactions of proteins. Regretfully, without this knowledge, it will be impossible to interpret the results of genome sequencing studies. Government and charitable organizations that fund biomedical research should be doing a much better job in coordination of genomics- and proteomics-based studies.
Link to the original blog post.