Some are exchanged via small loops of DNA called plasmids.

些基因会通过被称为质粒的DNA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质外，许多细菌含有额外的DNA分子，称为质粒。

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。

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。

Plasmids have relatively few genes and their genetic information is not essential to the bacterium and cells that lack them usually function normally.

质粒所含的基因相对较少，并且它们的基因对细菌说并不是必须的，缺少质粒的细胞往往也可以正常生长。

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，从本质上讲，这些质粒是在不同细菌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，在动些人类患者中。

Purification of the desired target fragment.

5。将片段与新的质粒载体连接组建个新的重组分子。

Initially, production in bacteria was the only route available and cDNA clones were used as they contained no introns.

cDNA需要与原核生的转录翻译信号相连，并且需要插入多拷贝的质粒。

But this is the first time the plasmid has been found in the United States, and it could get passed around quickly.

但这是第次在美国发现这种质粒，它可能会很快传播开。

Phage h can be used to clone fragments larger than plasmid vectors, and phage M13 allows cloned DNA to be isolated in single-stranded form.

更多载体被改造能同时拥有质粒噬菌体的些特性，像被称为粘粒的质粒-噬菌体λ杂体。

More specialized vectors have been engineered to use aspects of plasmids and bacteriophages, such as the plasmid-bacteriophage h hybrids known as cosmids

质粒噬菌体已经在很多种类的细菌中被使用表达基因，并且些噬菌体也许已经被用将DNA整合到宿主基因组上。

Or, in plain english, plasmids are part of the reason that, one day, antibiotics may not be able to help your strep throat anymore.

或者，用简单的英语说，质粒是有天抗生素可能无法再帮助您治疗链球菌性咽喉炎的部分原因。

I did all these experiments actually, with my own hands, I was 58 years old, I was still culturing plasmids and feeding cells, so it is very unlikely.

实际上，所有这些实验都是我亲手做的，当时我 58 岁，我还在培养质粒喂养细胞，所以这是非常不可能的。

The cytoplasm contains ribosomes which are the site of protein synthesis, the nucleoid which contains the genetic material, and plasmids which contain genes that confer a selective advantage to the bacterium.

细胞质中含有核糖体，它们是蛋白质合成的部位；拟核含有遗传质以及质粒；质粒含有赋予细菌选择性优势的基因。

This might be used to investigate a short region of a large cloned fragment in more detail, or to transfer a gene to a vector designed to express it in a particular species, for example.

以大肠杆菌中的质粒载体为例（最常见），这个过程可分为以下步骤。

And the thing that makes this mutation especially troubling is that it was found on a plasmid -- a little piece of DNA that can be easily shared between neighboring bacteria, meaning it can spread more easily.

让这种突变特别麻烦的是它是在质粒上发现的——段 DNA 可以很容易地在相邻细菌之间共享，这意味着它可以更容易地传播。

Vectors also incorporate a selectable marker, a gene which allows host cells containing the vector to be selected from amongst those which do not, usually by conferring resistance to a toxin, or enabling their survival under certain growth conditions.

最初的大肠杆菌载体是染色体外的形质粒，并且相当数量的噬菌体（感染细菌的病毒）也被用在大肠杆菌中。