Researchers suggest that RNA and DNA were created from RNA-DNA chimeras

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<div data-thumb = "https://scx1.b-cdn.net/csz/news/tmb/2019/researchpair.jpg" data-src = "https://scx2.b-cdn.net/gfx/ news / 2019 / researchpair.jpg "data-sub-html =" a, Representation of a constitutional formula of the three building blocks of oligonucleotides studied in this study b, Three possible scenarios for the emergence of RNA and DNA from prebiotic chemistry.Middle: the classic Global Concept of RNA in which the formation of a virgin and homogeneous RNA (or pre-RNA) leads to its DNA sequential (or RNA) sequences that transform into homogeneous RNA, which then gives rise to the DNA at the bottom: heterogeneous mixture of RNA-DNA that progresses and / or evolves simultaneously via RDNA sequences chimeric homogenous RNA and DNA simultaneously. Nature Chemistry (2019). DOI: 10.1038 / s41557-019-0322-x ">

<img src = "https://scx1.b-cdn.net/csz/news/800/2019/researchpair.jpg" alt = "Researchers suggest that RNA and DNA have been created from RNA-DNA chimeras "title =" a, Representation according to the constitutional formula of the three constituent blocks of the oligonucleotides studied in this study, b, Three possible scenarios for the emergence of the RNA and the DNA coming from the prebiotic chemistry, in the center: a classic global concept of RNA in which the formation of a virgin and homogeneous RNA (or pre-RNA) leads to its homogeneous DNA (or RNA) in the backbone. TNA (pre-RNA) and RNA forming chimeric RNA sequences that transform into homogeneous RNA, which then gives rise to DNA: a heterogeneous RNA-DNA mixture that progresses and / or evolves simultaneously via chimeric RNA sequences directly into homogeneous RNA and DNA simultaneously. Nature Chemistry (2019). DOI: 10.1038 / s41557-019-0322-x "/>
a, representation of constitutional formula of the three oligonucleotide building blocks studied in this study. b, Three possible scenarios for the emergence of RNA and DNA from prebiotic chemistry. In the middle: the classic concept of the world of RNAs in which the formation of a virgin and homogeneous RNA (or pre-RNA) leads to its homogeneous DNA sequence (or RNA). Top: Heterogeneous mixture of TNA (pre-RNA) and RNA forming chimeric RNA sequences that transform into homogeneous RNA, which then gives rise to a DNA. Bottom: Heterogeneous mixture of RNA-DNA that progresses and / or evolves simultaneously via chimeric RDNA sequences into homogeneous RNA and DNA simultaneously. Credit: Nature Chemistry (2019). DOI: 10.1038 / s41557-019-0322-x

Two researchers at the Scripps Research Institute have suggested that RNA and DNA began billions of years ago from RNA-DNA constructs containing RNA building blocks and d & # 39; DNA. In their article published in the newspaper Nature ChemistrySubhendu Bhowmik and Ramanarayanan Krishnamurthy expose their theory and argue that it makes more sense than the traditional explanation of how life began on Earth.


For many years, the consensus among scientists seeking to understand the origins of life was that a pre-RNA precursor with building blocks had appeared in the prebiotic soup. After that, the building blocks sort of formed into pre-RNA and finally into real RNA. Once this has happened, there has been a transition of both RNA and DNA. One of the main obstacles to the proof that such a scenario has led to the development of life is the impossibility of explaining how RNA could reproduce in a sustainable manner. In this new effort, Bhowmik and Krishnamurthy suggest that this was not necessary because RNA and DNA appeared in a different way. In their view, the constituents of RNA and DNA were both in the prebiotic soup. Over time, these constituents have been transformed into double-stranded chimeric RNA-DNA strands. And over time, these chimeras have turned into pure RNA and DNA.

To substantiate their theory, the researchers note that previous studies had shown that hybrid molecules made of RNA and DNA building blocks were less stable than RNA or DNA – some think it demonstrates why RNA, and then DNA, have become the basis of life. Bhowmik and Krishnamurthy were not in agreement, suggesting instead that weaker hybrid molecules would facilitate the transition of nature to pure RNA and DNA. This meant that the molecules were not prone to the replication problem with pure RNA. Lab tests have shown that when the RNA-DNA chimeras replicate, they preferentially form into separate RNA and DNA molecules, rather than into new chimeras. They recognize that no known living creature possesses a kind of chimeric RNA-DNA in its genome – but they also point out that other researchers have been able to force it to enter a genome of the genome. 39; E. Coli. And some other microorganisms make them seemingly accidental, but then eliminate them very quickly.

The building blocks of DNA and RNA could have appeared together before the start of life on Earth

More information:
Subhendu Bhowmik et al. The role of heterogeneity of sugar skeleton and chimeras in the simultaneous emergence of RNA and DNA, Nature Chemistry (2019). DOI: 10.1038 / s41557-019-0322-x

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The researchers suggest that RNA and DNA were created from RNA-DNA chimeras (September 17, 2019)
recovered on September 17, 2019
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