Organic #molecules delivered from #extraterrestrial materials may have played a key role in supplying building blocks for #life on #Earth.

Now scientists report all five canonical #nucleobases—purines (#adenine and #guanine) and pyrimidines (#cytosine, #thymine and #uracil)—in samples returned from the C-type #asteroid (162173) #Ryugu.

Samples from Ryugu, #Bennu and #Orgueil, which have a similar mineralogy and elemental composition, show purine-to-pyrimidine ratios negatively correlating with #ammonia.

These observations indicate that the nucleobases in these samples may have formed via a shared pathway depending on the physicochemical environment of the respective parent bodies.

The detection of diverse nucleobases in asteroid and meteorite materials demonstrates their widespread presence throughout the Solar System and reinforces the hypothesis that carbonaceous asteroids contributed to the #prebiotic chemical inventory of early Earth.

#astronomy #astrobiology
https://www.nature.com/articles/s41550-026-02791-z

A complete set of canonical nucleobases in the carbonaceous asteroid (162173) Ryugu - Nature Astronomy

Samples returned from the asteroid Ryugu contain all five canonical nucleobases (A, G, C, T and U). Their presence in Ryugu and Bennu supports the hypothesis that carbonaceous asteroids contributed to the prebiotic chemical inventory of early Earth.

Nature
SciTech Chronicles. . . . . . . . .Feb 13th, 2025

  In a world that rewards cruelty, it is brave to be kind. Vol II No 39 346 links Curated Euclid telescope spots rare 'Einstein ring' hiding...

❛❛ #adenine #guanine #cytosine #thymine & #uracil … necessary to build #DNA & #RNA … traces of important organic compounds like xanthine, hypoxanthine, & nicotinic acid (#vitamin B3).
In addition to suggesting that life could exist elsewhere in the #universe, the #molecules found on Bennu raise provocative questions about the #origins of #life on #Earth. ❜❜

#Bennu #asteroid was discovered in 1999 & sampled in 2020.

🔗 https://www.Salon.com/2025/01/30/building-blocks-of-life-discovered-on-asteroid-bennu/ 2025 Jan 30
🔗 https://Wikipedia.org/wiki/101955_Bennu

#Kronodon

Building blocks of life discovered on asteroid Bennu

The findings support theories that our evolution occurred thanks to space rocks colliding with our planet

Salon.com
This remarkable new #RNA-based #adenine and #cytosine base #editing system achieves targeted and efficient A-to-G and C-to-T conversions in lettuce, with potential applications in #crop breeding and #biotechnology.
https://doi.org/10.1111/jipb.13822
@wileyplantsci
#PlantSci #JIPB #CropSci #botany

The Basics of Purines and Pyrimidines: Understanding the Building Blocks of DNA and RNA

#Adenine, #CellSignaling, #Cytosine, #DNA, #EnzymeRegulation, #Guanine, #Purines, #Pyrimidines, #RNA, #Thymine, #Uracil #Genetics In the realm of molecular biology, few molecules are as crucial as purines and pyrimidines. These organic compounds serve as…. Medical Microbiology & Recombinant DNA Technology (RDT) Labs | Read More -

https://micrordt.wordpress.com/2024/05/15/the-basics-of-purines-and-pyrimidines-understanding-the-building-blocks-of-dna-and-rna/

The Basics of Purines and Pyrimidines: Understanding the Building Blocks of DNA and RNA

#Adenine, #CellSignaling, #Cytosine, #DNA, #EnzymeRegulation, #Guanine, #Purines, #Pyrimidines, #RNA, #Thymine, #Uracil #Genetics In the realm of molecular biology, few molecules are as crucial as …

Medical Microbiology & RDT Labs

Deciphering the Blueprint of Life: Exploring the Structure of DNA

#Adenine, #Blueprint, #Cytosine, #DeoxyriboseSugar, #DNA, #DNACoiling, #DoubleHelix, #Guanine, #Histone, #MajorGroove, #MinorGroove, #NitrogenousBases, #Nucleotide, #Phosphate, #StructureOfDNA, #Thymine, #WatsonAndCrick #Biochemistry, #Genetics The discovery of the structure of DNA stands as one of the most significant milestones in the history of science. Deoxyribonucleic acid, or DNA, is the molecule…

https://micrordt.wordpress.com/2024/04/27/deciphering-the-blueprint-of-life-exploring-the-structure-of-dna/

Deciphering the Blueprint of Life: Exploring the Structure of DNA

#Adenine, #Blueprint, #Cytosine, #DeoxyriboseSugar, #DNA, #DNACoiling, #DoubleHelix, #Guanine, #Histone, #MajorGroove, #MinorGroove, #NitrogenousBases, #Nucleotide, #Phosphate, #StructureOfDNA, #Th…

Medical Microbiology & RDT Labs
DNA Base Models

So to carry on with my project to build molecular models. I have built the 4 main base molecules associated with DNA dna structure infographic So t...

Paignton Library STEM Group
#Weeds in your #rice? Exploiting novel endogenous glyphosate-tolerant alleles has promising potential for weed control in rice breeding. Find out how it works! https://doi.org/10.1111/jipb.13543
@wileyplantsci
#JIPB #PlantSci #CropSci #cytosine #adenine #GeneEditing #evolution #botany #PLantScience
New NIOO publication: #Herbivory induced #methylation changes in the Lombardy #poplar: A comparison of results obtained by #epiGBS and #WGBS. #invertebrategenomics #cytosine #DNA #insects #plantgenomics
https://doi.org/10.1371/journal.pone.0291202
Herbivory induced methylation changes in the Lombardy poplar: A comparison of results obtained by epiGBS and WGBS

DNA cytosine methylation is an epigenetic mechanism involved in regulation of plant responses to biotic and abiotic stress and its ability to change can vary with the sequence context in which a cytosine appears (CpG, CHG, CHH, where H = Adenine, Thymine, Cytosine). Quantification of DNA methylation in model plant species is frequently addressed by Whole Genome Bisulfite Sequencing (WGBS), which requires a good-quality reference genome. Reduced Representation Bisulfite Sequencing (RRBS) is a cost-effective potential alternative for ecological research with limited genomic resources and large experimental designs. In this study, we provide for the first time a comprehensive comparison between the outputs of RRBS and WGBS to characterize DNA methylation changes in response to a given environmental factor. In particular, we used epiGBS (recently optimized RRBS) and WGBS to assess global and sequence-specific differential methylation after insect and artificial herbivory in clones of Populus nigra cv. ’italica’. We found that, after any of the two herbivory treatments, global methylation percentage increased in CHH, and the shift was detected as statistically significant only by epiGBS. As regards to loci-specific differential methylation induced by herbivory (cytosines in epiGBS and regions in WGBS), both techniques indicated the specificity of the response elicited by insect and artificial herbivory, together with higher frequency of hypo-methylation in CpG and hyper-methylation in CHH. Methylation changes were mainly found in gene bodies and intergenic regions when present at CpG and CHG and in transposable elements and intergenic regions at CHH context. Thus, epiGBS succeeded to characterize global, genome-wide methylation changes in response to herbivory in the Lombardy poplar. Our results support that epiGBS could be particularly useful in large experimental designs aimed to explore epigenetic changes of non-model plant species in response to multiple environmental factors.

With an improved dual #cytosine and #adenine #BaseEditor, Zhang et al. target OsEPSPS for artificial #evolution, generating a novel allele conferring glyphosate tolerance in #rice.
https://doi.org/10.1111/jipb.13543
@wileyplantsci
#JIPB #PlantSci #CropScience #PlantScience