<<返回上一页

Good relations

发布时间:2019-03-08 05:03:01来源:未知点击:

TYPHUS has killed millions of people through the ages, but new research shows that humans owe their existence to a relative of this deadly microbe. This week, Charles Kurland and his colleagues at the University of Uppsala in Sweden announced that they had sequenced all 1 111 523 DNA bases of Rickettsia prowazekii, the typhus bacterium (Nature, vol 296, p 133). Analysis of R. prowazekii’s genes revealed that it is the closest known relative of mitochondria, the DNA-containing structures that produce the energy on which all higher cells depend. Biologists have long believed that mitochondria are the descendants of bacteria that learnt to live symbiotically within animal cells. The researchers say R. prowazekii represents an earlier point in this evolution,