Gene Expression and Cell Specialization · 基因表达与细胞特化
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| differentiation/ˌdɪfəˌrenʃɪˈeɪʃn/ | 分化 | fēn huà |
| stem cell/stem sel/ | 干细胞 | gàn xì bāo |
Same DNA, very different cells
- A nerve cell, a muscle cell, and a red blood cell look nothing alike.
- Yet every one of them carries the exact same DNA.
- How can identical instructions build such different cells?
- The answer lies in which genes each cell switches on.
相同的 DNA,非常不同的细胞
- 一个神经细胞、一个肌肉细胞和一个红细胞看起来毫不相像。
- 然而它们每一个都携带完全相同的 DNA。
- 相同的指令怎么能构建出如此不同的细胞?
- 答案在于每个细胞开启哪些基因。
Differentiation
- Early cells are unspecialized; over time they become specialized.
- This process is called differentiation 分化.
- A cell takes on a specific shape and job — carrying oxygen, contracting, signalling.
- Once specialized, it usually keeps that role for life.
分化
- 早期的细胞是未特化的;随时间它们变得特化。
- 这个过程叫做分化(differentiation)。
- 细胞采取一个特定的形状和工作——运输氧气、收缩、传信号。
- 一旦特化,它通常终生保持那个角色。
Differentiation · 微分 is the process by which a cell… · 分化是细胞……的过程。
Differentiation · 微分 is a cell becoming specialized — a muscle cell, a nerve cell, and so on. · 分化是细胞变得特化——一个肌肉细胞、一个神经细胞,等等。
Different genes, different cells
- Every cell has the same genes but expresses a different set.
- A muscle cell switches on contraction genes; a red blood cell switches on haemoglobin genes.
- This is why cells with identical DNA end up so different.
- Specialization is about gene expression, not different DNA.
不同的基因,不同的细胞
- 每个细胞都有相同的基因,但表达一套不同的基因。
- 肌肉细胞开启收缩基因;红细胞开启血红蛋白基因。
- 这就是为什么有相同 DNA 的细胞最终如此不同。
- 特化关乎基因表达,而不是不同的 DNA。
How can cells with the same · 相同 DNA become so different? · 有相同 DNA 的细胞怎么能变得如此不同?
Every cell has the same genes but switches on a different set — this is differential gene expression. · 每个细胞都有相同的基因,但开启一套不同的基因——这就是差异基因表达。
A specialized cell keeps all its genes, but only expresses some of them. · 一个特化的细胞保留它所有的基因,但只表达其中一些。
Specialization comes from switching genes on and off, not from losing genes. · 特化来自开启和关闭基因,而不是来自丢失基因。
Stem cells
- A stem cell 干细胞 has not yet specialized.
- It can still develop into many different cell types.
- Your body uses stem cells to grow and to repair damage.
- As a stem cell differentiates, it locks in a particular pattern of gene expression.
干细胞
- 干细胞(stem cell)还没有特化。
- 它仍然能发育成许多不同的细胞类型。
- 你的身体用干细胞来生长和修复损伤。
- 当一个干细胞分化时,它锁定一个特定的基因表达模式。
Which cell expresses which genes? · 哪种细胞表达哪些基因?
Sort each specialized job by the cell type whose genes are switched on to do it. · 按照哪种细胞类型开启基因来做它,给每项特化的工作分类。
An unspecialized cell that can develop into many cell types is a ____ cell. · 一个能发育成许多细胞类型的未特化细胞是一个____细胞。
A stem cell has not yet specialized, so it can still become many different cell types. · 干细胞还没有特化,所以它仍然能变成许多不同的细胞类型。
Select all · 所有 true statements about cell specialization. · 选出关于细胞特化的所有正确说法。
Cells keep all their genes; they just do not express the unused ones. The other three are correct. · 细胞保留它们所有的基因;它们只是不表达未使用的那些。其余三条正确。
Specialized cells do not throw away the genes they are not using. A muscle cell still carries the haemoglobin gene — it just keeps it switched off. Every cell holds the full genome; specialization is which genes are expressed.
特化的细胞不扔掉它们不使用的基因。一个肌肉细胞仍然携带血红蛋白基因——它只是让它保持关闭。每个细胞都持有完整的基因组;特化是哪些基因被表达。
A red blood cell versus a neuron:
- Both start with the same complete DNA.
- The red blood cell switches on haemoglobin genes and even loses its nucleus to carry more oxygen.
- The neuron instead grows a long axon and switches on signalling genes — same genome, opposite jobs.
一个红细胞对比一个神经元:
- 两者都从相同的完整 DNA 开始。
- 红细胞开启血红蛋白基因,甚至失去它的细胞核以携带更多氧气。
- 神经元则长出一条长长的轴突并开启信号基因——同样的基因组,相反的工作。
Cells with identical DNA become different through differentiation, expressing a different set of genes. A muscle cell and a nerve cell run different genes from the same genome. A stem cell is unspecialized and can still become many cell types. Specialization is about gene expression, not gene loss.
有相同 DNA 的细胞通过分化变得不同,表达一套不同的基因。一个肌肉细胞和一个神经细胞从同一个基因组运行不同的基因。干细胞是未特化的,仍然能变成许多细胞类型。特化关乎基因表达,而不是基因丢失。