科研人员发现，被动吸烟导致小鼠精子发生遗传突变。在美国，处于生殖年龄的男性其中1/3以上吸烟，此前的研究已确定了这些人处于精子缺陷的高风险行列，包括精子运动性差和DNA损伤，这些异常可导致自发流产和出生缺陷。
别以为被动吸烟只对女性有害
Francesco Marchetti及其同事试图回答公共卫生专家长久以来面临的一个问题：被动吸烟会导致可遗传的遗传变化吗？作者在2周内让雄性小鼠接触被动吸烟的一种成分，它含有数十种致癌物质。6周后，对这些小鼠的精液进行了一次遗传分析。接触被动吸烟成分的小鼠，它的精子DNA在遗传突变标记区内具有很高的突变率。相比之下，小鼠的红细胞在接触同样成分的情况下却没有提高的突变率，表明精子可能对二手烟的致畸效应特别敏感。因此，被动吸烟可导致有害后果——雄性精子的遗传突变。
生物探索推荐英文摘要
Passive smoking might affect male reproductive success
Abstract: Researchers have found that passive smoking leads to genetic mutations in mouse sperm. More than a third of men of reproductive age in the United States are smokers, who, previous studies have established, are at a high risk of suffering sperm defects, including sperm immobility and DNA damage. Those abnormalities can lead to spontaneous abortions and birth defects. Francesco Marchetti and colleagues attempted to answer a longstanding question facing public health experts: Does passive smoking lead to heritable genetic changes" For 2 weeks, the authors exposed male mice to a component of passive tobacco smoke, called sidestream smoke, which contains dozens of carcinogens. Six weekslater, the authors performed a genetic analysis on sperm from the mice, and found that mice exposed to sidestream smoke had a high rate of mutations in a region of the sperm DNA known to be an established marker for heritable mutations. By contrast, sidestream smoke did not increase the rate of mutations in the red blood cells of the mice, suggesting that sperm might be particularly sensitive to the mutagenic effects of second-hand smoke. The authors' findings suggest that passive smoking might lead to similar negative consequences.
