Some are exchanged via small loops of DNA called plasmids.

一些基因会通过被称为质粒的DNA小环交换。

Additionally to the genetic material contained within the nucleoid, many bacteria contain extra chromosomal DNA molecules called plasmids.

除了包含在拟核中的遗传物质外，许多细菌含有额外的DNA分子，称为质粒。

Then they dropped the plasmid into a living bacterium, or yeast.

然后他们将质粒放入活细菌或酵母中。

However, plasmids often contain genes that confer a selective advantage to the bacterium such as resistance to antibiotics.

不过质粒通常包含赋予细菌选择性优势的基因，例如抗生素耐药性。

These plasmids are small double-stranded DNA molecules that can exist independently of the chromosome and they can be circular or linear.

它们是双链的DNA小分子，可以独立于细菌染色体（拟核）而存在，可以是环状或线状的。

Transfer of the ligated plasmid into an E. coli strain (transformation).

7。转化成功的细菌的筛选。

The plasmid enters and multiplies itself within a cell and can then be transferred to others.

质粒进入细胞并在细胞内繁殖， 然后可以转移到其他细胞中。

So essentially, these plasmids are the vehicles that transfer genes for antibiotic resistance between different bacterial species.

因此本质上，这些质粒是在不同细菌物种之间转移抗生素抗性基因的载体。

This plasmid mutation has been seen in other places before; in China, in animals and some human patients.

这种质粒突变以前在其他地方也见过；在中国，在动物和一些人类患者中。

The cDNAs had to be linked to prokaryotic transcription and translation signals and inserted into multicopy plasmids.

然而，占总蛋白30%的过量表达的蛋白质是沉淀或不溶的形式并且缺少翻译后修饰。