Marian A J, Roberts R
Baylor College of Medicine, Houston, Texas.
Herz. 1993 Aug;18(4):203-12.
The genetic information for the development of an organism is stored and inherited by deoxyribonucleic acid (DNA). In higher organisms the DNA is located within the cell nucleus. DNA has the structure of a double helix and contains a specific sequence of four types of nucleotides that are specified by the bases adenine, guanine, cytosine and thymine. Replication of the DNA double helix by DNA polymerase results in the formation of two double helices with identical nucleotide sequences. Expression of the information contained in the DNA requires the synthesis of ribonucleic acid (RNA) copies and subsequent transport of the RNA from the nucleus to the cytoplasm. One type of RNA, called messenger RNA (mRNA), contains the instruction for the amino acid sequence of polypeptides. The translation of the nucleotide sequence of mRNA into the amino acid sequence of polypeptides is facilitated by ribosomes. For the synthesis of each of the different kinds of polypeptides a specific mRNA is expressed. The expression of the genetic information is mainly regulated by direct interactions of control elements located on DNA and RNA with certain protein factors.
生物体发育的遗传信息由脱氧核糖核酸（DNA）储存并遗传。在高等生物中，DNA位于细胞核内。DNA具有双螺旋结构，包含由腺嘌呤、鸟嘌呤、胞嘧啶和胸腺嘧啶碱基指定的四种核苷酸的特定序列。DNA聚合酶对DNA双螺旋的复制导致形成两个具有相同核苷酸序列的双螺旋。DNA中所含信息的表达需要合成核糖核酸（RNA）拷贝，并随后将RNA从细胞核转运到细胞质。一种称为信使RNA（mRNA）的RNA包含多肽氨基酸序列的指令。核糖体有助于将mRNA的核苷酸序列翻译成多肽的氨基酸序列。为了合成每种不同类型的多肽，会表达一种特定的mRNA。遗传信息的表达主要通过位于DNA和RNA上的控制元件与某些蛋白质因子的直接相互作用来调节。
