雅艾尔：嘿，唐，你能说出你体内三种干细胞的名称吗?
Don: I've thought stem cells were from Embryos,Yael, do adult have them, too?
唐：我一直以为干细胞来自于胚胎，雅艾尔，成人体内也有吗?
Yael: We've got a few kinds of stem cells, each witha different role. The term “potency” is used todescribe the capacity of cells to change, ordifferentiate, into different cell types when theydivide. There are totipotent, pluripotent, multipotent, oligopotent and unipotent cells.
雅艾尔：我们体内有一些不同种类的干细胞，每种都有不同的作用。“效能”这个术语是用来描述细胞分裂时，分化成为不同类型细胞的能力。按“功效”可分为全能性干细胞、多能性干细胞、专能性干细胞和单能性干细胞。
Don: Wow! How about some examples?
唐：哇!能举些例子么?
Yael: Sure, a fertilized egg cell as it divides makes every kind of cell in the human body. Thatone cell can create an entire person. So a fertilized egg is an example of totipotency. Embryonicstem cells are almost as flexible. They can differentiate into almost any cell type, like lung,muscle, liver, skin or brain cells. But a single embryonic stem cell can never grow into an entireorganism. This is an example of pluripotency.
雅艾尔：当然，人体内的一个受精卵细胞在分裂的时候会产生很多种不同的细胞。一个细胞创造了完整的人体。所以受精卵就是一种全能性干细胞。胚胎干细胞与之同样灵活。胚胎干细胞能够分化成几乎所有的细胞类型，像肺、肌肉、肝脏、皮肤或者脑细胞。但一个胚胎干细胞不能长成一个完整的器官。因此它是多能性干细胞的一个例子。
Don: My friend had a Stem Cell Transplants as a treatment for leukemia. What kind of stemcells of those?
唐：我的朋友在治疗白血病的时候接受了干细胞移植，这又是哪一种干细胞呢?
Yael: She probably received a donation of blood stem cells, like those found in bone marrow.Blood stem cells are multipotent. They can make all the different blood cell types, like red andwhite blood cells or platelets. But they can't create other kinds of cells. An example ofoligopotency lurks in your lymph nodes. Lymphoid stem cells can produce a few, but not all,kinds of blood cells. Finally, cells that only produce identical copies of themselves are calledunipotent. Like skin cells, when they divide, they only make more skin cells.
雅艾尔：她可能接受的是骨髓中的造血干细胞。造血干细胞是多能性干细胞，它们可以生产各种类型的血细胞，例如红细胞、白细胞或者血小板。但是不能生产其他种类的细胞。专能性干细胞的一个例子潜伏在你的淋巴结里。淋巴干细胞能制造一些、但非全部的血细胞。最后，只能复制自己的干细胞被称为单能性干细胞，例如表皮细胞，这些细胞再分裂时只能形成表皮细胞。
