PTE听力口语-科学60秒:Insects horizontal DNA genetic transfer

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听力内容:

60秒科学节目(SSS)是科学美国人网站的一套广播栏目,英文名称:Scientific American – 60 Second Science,节目内容以科学报道为主,节目仅一分钟的时间,主要对当今的科学技术新发展作以简明、通俗的介绍,对于科学的发展如何影响人们的生活环境、健康状况及科学技术,提供了大量简明易懂的阐释。

 

This is Scientific American — 60-Second Science. I’mChristopher Intagliata.
You can thank your parents for your DNA. Becausehumans share genes through sexual reproduction, passing DNA from parent to child. It’s known as the’vertical transfer’ of DNA.
Now imagine if you could share just one or two bitsof your DNA with an unrelated stranger, through a handshake, or other incidental contact—and that stranger inserted your DNA into their genome. No sex. No offspring either. That’scalled the ‘horizontal transfer’ of DNA. It’s obviously not how humans do it. But it’s a mainstayof single-celled organisms like bacteria, which use the process to share antibiotic resistancegenes, for example.

And now French scientists have found that horizontal DNA transfer could be a lot morecommon than we thought in multicellular organisms, too—insects, in this case. Because byanalyzing 195 insect genomes, they found more than 2,200 cases of horizontal DNA transferbetween unrelated species of flies and butterflies, beetles and wasps.
That total quadruples the number of horizontal DNA transfers previously described in allplants, animals and fungi. The study is in the Proceedings of the National Academy of Sciences.
How exactly this genetic transfer happens is still a mystery. Might be viruses, or parasites, doing the DNA delivery. But whatever the cause, it suggests that the evolution of insects, ona molecular level at least, may be something more of a shared success story.
Thanks for listening for Scientific American — 60-Second Science Science. I’m ChristopherIntagliata.

 

 

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