The second-largest genome ever sequenced belongs to a small but fascinating creature. Called “xiao qiang” or “little mighty” in China, the American cockroach has a genome larger than that of humans.

　　人类目前测序完毕的第二大基因组属于一种神奇的小生物。它叫做美洲大蠊，在中国被称为“小强”，其基因组比人类的还要庞大。

　　It’s genetic code holds the secrets to how these insects can survive on so many different types of food and in such unfriendly habitats, or even how it can survive for a week without a head and grow replacement limbs.

　　这种昆虫如何以各色食物维生，如何在恶劣环境下生存，又是如何在没有头的情况下存活一周并长出新的肢体?这一切奥秘都隐藏在其遗传密码之中。

　　Researchers at South China Normal University in Guangzhou sequenced the genome of the hardy insect and published their findings in Nature Communications last week.

　　广州华南师范大学的研究人员对这种顽强昆虫的基因组进行了测序，并把研究成果发表在了上周的《自然通讯》(Nature Communications)上。

　　They found that the groups of genes related to the immune system, sensory perception, detoxification, and growth and reproduction were all enlarged, helping to explain how cockroaches are able to live in so many different environments — and why it’s so hard to kill them.

　　他们发现，蟑螂有关免疫系统、感官知觉、解毒、生长和繁殖的基因组十分庞大，这解释了它们为何可以存活于各种各样的环境中——以及为何难以被杀死。

　　“It’s a tiny pest, but has very strong vitality,” Sheng Li, the lead author of the paper and entomology professor, told the New York Times.

　　昆虫学家、论文的第一作者李胜在接受《纽约时报》(New York Times)采访时表示：“这种昆虫很小，却有很强的生命力。”

　　Since sequencing the first human genome, which took more than a decade and nearly $2.7 billion, medical researchers have found ways to make organisms resistant to disease. Also, CRISPR technology has moved the medical field toward cheap and and easy DNA editing.

　　自花费十余年时间、耗资近27亿美元对人类基因组首次测序以来，医学研究人员就找到了赋予生物体抗病能力的途径。此外，CRISPR(规律成簇的间隔短回文重复)技术也推动着医疗领域向廉价和简便的DNA编辑方面发展。

　　Scientists are looking to species like the American cockroach to learn about how traits that make them incredible adapters and stubborn survivalists are encoded in their DNA. Compared to other insects, the American cockroach genome is larger than any known genome sequence except locusts.

　　科学家正在研究美洲大蠊等物种，探究那些让它们适应性和生命力如此强大的性状在DNA中的编码方式。除了蝗虫以外，美洲大蠊的基因组比其他任何已知昆虫的基因组都要庞大。

　　Here are a variety of ways this information about roaches can help humans:

　　蟑螂的基因信息可以从以下几个方面帮助人类：

　　Safety

　　安全

　　The researchers found that American cockroaches have more than 1,000 genes that help them read chemical cues in their environment.

　　研究人员发现，美洲大蠊拥有超过1,000个基因帮助它们辨识环境中的化学物质。

　　More than 300 of these genes relate to sensing bitter tastes, giving cockroaches plenty of information about which foods are and are not safe to eat. The bugs also have genes that allow them to withstand toxic environments and a higher number of enzymes that break down toxins in addition to their stronger immune systems.

　　其中超过300个基因都与苦味感受相关，蟑螂可以借此获取大量有关食物是否安全的信息。还有一些基因可以帮助它们抵御有毒环境，产生大量分解毒素的酶类，并强化免疫系统。

　　Pest Control

　　害虫防治

　　The genes that show why cockroaches are so hardy also give clues about how to get rid of them.

　　这些基因在体现蟑螂顽强生命力的同时，也可以让人类找出摆脱它们的方式。

　　Scientists manipulated more than 20 genes related to the immune system, reproductive system, and development, revealing damaging effects on the insects. This could show a path toward creating new pest control methods, similar to the genetically embedded insecticides Monsanto has developed.

　　科学家修改了这些昆虫有关免疫系统、生殖和发育系统的超过20个基因，给它们带来了毁灭性的影响。这为害虫防治开辟了新的道路，类似于孟山都(Monsanto)开发的基因嵌入式杀虫剂。

　　Healing Properties

　　自愈特性

　　The American cockroach will regenerate lost limbs. By amputating limbs during their research and monitoring their regrowth, scientists found that genes in the cockroach’s DNA prompt healing and regeneration.

　　美洲大蠊可以再生失去的肢体。科学家在试验中切掉了它们的肢体，观察了再生过程，发现蟑螂的DNA会促进愈合和再生。

　　Cockroaches have long been used in traditional Chinese medicine for treating cuts and burns, but researchers will study how the insects generate new tissue in hopes of unlocking future medical applications for humans.

　　在传统中药里，蟑螂一直被用于治疗割伤和烧伤，但研究人员将进一步探索这些昆虫如何产生新的组织，希望借此开辟人类医疗上的新未来。

　　“We’ve uncovered the secret of why people call it ‘xiao qiang,’ ” Li said. “Now we want to know the secrets of Chinese medicine.”

　　李胜表示：“我们知道了它得名‘小强’的秘密，现在我们希望发掘中药里的秘密。”

　　Social Behaviors

　　社会行为

　　By studying cockroaches and termites, scientists hope to uncover the genetic origins of eusociality, which causes organisms to work together and cooperate in dividing labor.

　　科学家希望通过研究蟑螂和白蚁，发掘昆虫社会性——即它们进行分工合作——的遗传来源。

　　Termites, which recent research shows are more closely related to cockroaches than originally thought, developed this trait much earlier than insects like bees and ants.

　　通过最近的研究，人们发现白蚁与蟑螂的关系较以往所认为的更近，它们比蜜蜂和蚂蚁等昆虫更早演化出了这一特性。