Biochemical controls: editing DNA mistakes (Introduction)

by David Turell , Sunday, September 08, 2024, 18:49 (74 days ago) @ David Turell

How alternative splicing is used:

https://www.sciencedaily.com/releases/2024/09/240902111806.htm

"Alternative splicing is a genetic process where different segments of genes are removed, and the remaining pieces are joined together during transcription to messenger RNA (mRNA). This mechanism increases the diversity of proteins that can be generated from genes, by assembling sections of genetic code into different combinations. This is believed to enhance biological complexity by allowing genes to produce different versions of proteins, or protein isoforms, for many different uses.

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"The research team, led by Yang Li, PhD, Benjamin Fair, PhD, and Carlos Buen Abad Najar, PhD, analyzed large sets of genomic data, covering various stages from early transcription to when RNA transcripts are destroyed by the cell. They saw that cells produced three times as many "unproductive" transcripts -- RNA molecules with mistakes or unexpected configurations -- as when they analyzed steady-state, finished RNA only.

"Unproductive transcripts are quickly destroyed by a cellular process called nonsense-mediated decay (NMD). Li's team calculated that on average, about 15% of transcripts that are started are almost immediately degraded by NMD; when they looked at genes with low expression levels, that number went up to 50%. (my bold)

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"Li believes cells sometimes purposely select transcripts doomed for NMD to decrease expression levels. If the nascent RNA is destroyed before it gets fully transcribed, it will never produce proteins to execute biological functions. This effectively silences the genes, like deleting an email draft before its writer can press send.

"'We found that genetic variations that increase unproductive splicing often decreased gene expression levels," Li said. "This shows that there this mechanism must have some effect on expression, because it is so widespread."

"The team found that many variants linked to complex diseases are also associated with more unproductive splicing and decreased gene expression.

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"'We think we can target a lot of genes because now we know how much this process is going on," Li said. "People used to think that alternative splicing was mainly a way to make an organism more complex by generating different versions of proteins. Now we're showing that it might not be its most important function. It could be simply to control gene expression.'"

Comment: what interests me here is the editing system to control mistakes. It applies directly to our theodicy discussion. My view is God clearly recognized the need for editing when the molecules were necessarily free and uncontrolled in their actions as they followed the given instructions. The article clearly shows the level of mistakes. (15 to 50%)