ミシガン大学による新たな研究は、有益な突然変異は従来考えられていたよりも一般的であるものの、環境変化が激しいために定着しないことが多いと示唆している。この研究は、分子進化に対する修正された見解を提示している。
張建之教授率いる研究チームは、深層突然変異スキャンを用いて酵母と大腸菌の変異を調査した。その結果、アミノ酸を変化させる変異のうち1パーセント以上が有益であることが判明し、安定した条件下では置換の99パーセント以上が適応的であるはずだと示唆された。しかし、この割合は自然界で観察されるものよりはるかに高い。
AIによるレポート AIによって生成された画像 事実確認済み
Researchers at Hokkaido University report that cells left with an extra set of DNA after a division error can have markedly different outcomes depending on how the division fails—findings that could help explain why some abnormal cells persist in diseases where whole-genome duplication is common, including cancer.
A federally funded mouse study has revealed that some inherited traits follow non-Mendelian patterns through epigenetic changes. The research identified hundreds of unexpected DNA methylation events across generations. It also documented the first known natural paramutation in a mammal.
AIによるレポート
A 20-year experiment cloning mice has revealed that clones develop significantly more genetic mutations than naturally reproduced mice, accumulating to fatal levels after multiple generations. Researchers led by Teruhiko Wakayama at Yamanashi University in Japan found over 70 mutations per clone generation on average, three times higher than in controls. The findings, published in Nature Communications, raise concerns for applications in farming, conservation and de-extinction efforts.
Researchers at the Earth-Life Science Institute in Tokyo have shown through experiments that repeated freezing and thawing could have driven the growth and fusion of primitive cell-like structures on early Earth. Vesicles made with certain lipids fused into larger compartments and retained DNA more effectively during these cycles. The findings suggest icy environments played a role in life's origins.
AIによるレポート
Researchers have discovered that distantly related butterflies and moths have used the same two genes, ivory and optix, for more than 120 million years to create similar warning colors on their wings. This finding suggests evolution can follow predictable genetic pathways rather than being entirely random. The study focused on species from South American rainforests.