Luo Haiwei
Institute of Environment, Energy, and Sustainability, The Chinese University of Hong Kong, Shatin, Hong Kong SAR.
Department of Earth and Environmental Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR.
Ann Rev Mar Sci. 2025 Jan;17(1):537-560. doi: 10.1146/annurev-marine-050823-104415. Epub 2024 Nov 25.
Genome-reduced bacteria constitute most of the cells in surface-ocean bacterioplankton communities. Their extremely large census population sizes ( ) have been unfoundedly translated to huge effective population sizes ( )-the size of an ideal population carrying as much neutral genetic diversity as the actual population. As scales inversely with the strength of genetic drift, constraining the magnitude of is key to evaluating whether natural selection can overcome the power of genetic drift to drive evolutionary events. Determining the of extant species requires measuring the genomic mutation rate, a challenging step for most genome-reduced bacterioplankton lineages. Results for genome-reduced and CHUG are surprising-their values are an order of magnitude lower than those of less abundant lineages carrying large genomes, such as and . As bacterioplankton genome reduction commonly occurred in the distant past, appreciating their population genetic mechanisms requires constraining their ancient values by other methods.
基因组精简的细菌构成了表层海洋浮游细菌群落中的大部分细胞。它们庞大的普查种群规模（ ）被无端地转化为巨大的有效种群规模（ ）——即一个理想种群的规模，其携带的中性遗传多样性与实际种群一样多。由于 与遗传漂变的强度成反比，限制 的大小是评估自然选择是否能够克服遗传漂变驱动进化事件的能力的关键。确定现存物种的 需要测量基因组突变率，这对大多数基因组精简的浮游细菌谱系来说是具有挑战性的一步。基因组精简的 和CHUG的结果令人惊讶——它们的 值比那些携带大基因组的丰度较低的谱系（如 和 ）低一个数量级。由于浮游细菌基因组精简通常发生在遥远的过去，要了解它们的群体遗传机制需要通过其他方法来限制它们古老的 值。
