What'sNEW
| 07 Feb 2025 |
What'sNEW about HGT
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...a large exogenous bacterial chromosome placed in a eukaryotic context spontaneously adopts eukaryotic chromatin features....
French specialists in genomics and related fields observe this, following experiments introducing bacterial DNA into yeast cells. Perhaps the acquisition of diverse sequences very long ago led to eukaryotic chromatin compartmentalization? The whole subject of eukaryotic DNA supplied by HGT is waiting for exploration.
 "Sequence-dependent activity and compartmentalization of foreign DNA in a eukaryotic nucleus," by Léa Meneu, Christophe Chapard et al, doi:10.1126/science.adm9466; and "Relating DNA sequence, organization, and function" [commentary], by Geoffrey Fudenberg and Vijay Ramani, Science, 07 Feb 2025.
 Viruses... has a primer and links about HGT from bacteria to eukaryotes.
| 04 Feb 2025 |
What'sNEW about HGT
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...multiple independent events of microbe-to-beetle HGT and specialized symbioses drove convergent evolutionary innovations in approximately 21,000 and 13,500 leaf beetle species, respectively.
This statement comes from an international consortium including veteran entomologists and evolutionary biologists. Their new report makes clear that HGT is a frequent contributor to evolutionary advances in these eukaryotes.
"Symbiosis and horizontal gene transfer promote herbivory in the megadiverse leaf beetles," by Roy Kirsch et al, doi:10.1016/j.cub.2024.12.028; and "Insect herbivory..." [commentary], by Noah K. Whiteman, Current Biology, 03 Feb 2025.
 Thanks, Google Alerts.
...among the most compelling detections were amino acids – 14 of the 20 that life on Earth uses to make proteins – and all five nucleobases that life on Earth uses to store and transmit genetic instructions....
This comment comes from one of two large interdisciplinary teams who have analysed samples returned from asteroid Bennu. Fifty years ago, all of the organics would have been thought incredible, but this surprise has been gradually accepted and explained. Now they are considered to be ingredients for the Earthly origin of life, a concept I call pseudo-panspermia. With my opposite gestalt, I suspect that these life-related molecules actually came from life — the simplest way to explain them. I would be surprised if no signs of life were found in space.
The other team (McCoy et al.) was focussed on the minerals in the samples, which must have precipitated from a watery brine on Bennu's parent body. The evidence for liquid water in the asteroids moons of our solar system is another ongoing surprise that also looks favorable for panspermia. Analysis of the valuable Bennu samples is not complete.
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Bennu's valine exhibits life's chiralty (Glavin et al.)
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"Abundant ammonia and nitrogen-rich soluble organic matter in samples from asteroid (101955) Bennu," by Glavin, D.P., Dworkin, J.P., Alexander, C.M.O. et al, doi:10.1038/s41550-024-02472-9, Nature Astronomy, 29 Jan 2025.
"An evaporite sequence from ancient brine recorded in Bennu samples," by McCoy, T.J., Russell, S.S., Zega, T.J. et al, doi:10.1038/s41586-024-08495-6, Nature, 29 Jan 2025; and commentary:
"NASA's Asteroid Bennu Sample Reveals Mix of Life's Ingredients," by Jessica Taveau, NASA, 29 Jan 2025.
"Bennu asteroid...," by Timothy J McCoy and Sara Russell, The Conversation and Smithsonian, 29 Jan 2025.
"Lurking Inside an Asteroid: Life's Ingredients," by Carl Zimmer, The New York Times, 29 Jan 2025.
"Asteroid Bennu contains salts from ancient brine," by Yasuhito Sekine, Nature, 29 Jan 2025.
"Are we all aliens?...," by Marcia Dunn, Phys.Org, 01 Feb 2025.
Thanks for alerts, Patsy Welch and Kenneth Augustyn.
Comet Rendezvous has discussion and updates.
Comets: The Delivery System has background and related discussion.
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