アールハム研究所の研究チームは、これまで知られていなかった原生生物の一種を特定した。この生物は、通常は翻訳終了を意味する2つの遺伝的終止コドンをアミノ酸の指定に転用しており、生命の標準的な遺伝規則からの稀な逸脱を示す発見となった。
この生物「Oligohymenophorea sp. PL0344」は、単細胞DNAシーケンシング手法の定期試験の最中にオックスフォード大学公園内の淡水池から採取された。研究を主導した博士研究員のジェイミー・マクゴーワン博士は、今回の発見を純粋な偶然であると述べ、原生生物の遺伝学について我々がいかに理解していないかを浮き彫りにするものだと指摘した。この繊毛虫において、コドン「TAA」と「TAG」はもはや遺伝子の終結を告げるものではなく、それぞれリシンとグルタミン酸を指定するようになっており、終止コドンとしては「TGA」のみが機能している。
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Researchers at Kyoto University and RIKEN report that human cells can detect “non-optimal” synonymous codons—alternative three-letter genetic instructions that encode the same amino acid but are translated less efficiently—and selectively suppress the corresponding mRNAs. In experiments described in Science, the team identifies the RNA-binding protein DHX29 as a central component of this codon-dependent control of gene expression.
Researchers at the University of California, Berkeley have identified a methane-producing archaeon that interprets a standard stop codon in two ways, challenging a core principle of biology. The microbe, Methanosarcina acetivorans, sometimes adds an amino acid called pyrrolysine instead of halting protein synthesis. This flexibility may aid in metabolizing compounds linked to human health.
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Researchers have discovered genes that duplicated before the last universal common ancestor of all life, offering insights into evolution's earliest stages. These universal paralogs, present in nearly every organism, suggest protein production and membrane transport were among the first biological functions. The findings, published in Cell Genomics, highlight how ancient genetic patterns can reveal pre-LUCA history.
Samples from asteroid Bennu, returned by NASA's OSIRIS-REx mission in 2023, contain amino acids that likely formed in frozen ice exposed to radiation, according to new research. Penn State scientists analyzed isotopes in the material, challenging traditional views of amino acid origins. The findings, published on February 9, highlight diverse pathways for life's building blocks in the early solar system.
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Researchers at Caltech have discovered how viruses infect bacteria by disabling a key protein called MurJ, essential for cell wall construction. This mechanism, revealed through high-resolution imaging, suggests a new approach to combating antibiotic-resistant superbugs. The findings highlight convergent evolution in unrelated viruses blocking MurJ similarly.
Researchers have discovered that DNA in newly fertilized eggs forms a structured 3D scaffold before the genome activates, challenging long-held assumptions. Using a new technique called Pico-C, scientists mapped this organization in fruit fly embryos. A related study shows that disrupting this structure in human cells triggers an immune response as if under viral attack.
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Researchers at the University of Waterloo have developed engineered bacteria designed to invade and eat solid tumors from the inside out. The approach uses microbes that thrive in oxygen-free environments, targeting the low-oxygen cores of tumors. A genetic modification allows the bacteria to survive near oxygenated edges, controlled by a quorum-sensing mechanism.