醫(yī)學英語-genetics-遺傳學

1、Genetics,Huang Tian, APSUMC,Outline,Basic concepts of geneticsGenetic disordersGenetic engineering,? By the end of this section, students should be able to – Master basic concepts of genetics – Describe the stru

2、cture of DNA – Describe the process of gene expression – Classify categories of genetic disorders – Describe four basic steps in genetic engineering – Define PCR and list the three steps of PCR,Objectives,Ge

3、ne,ChromosomeGeneDNA,Hereditary遺傳單位 unit,Locating genes,The structure of DNA,核苷酸,Base pairing rules,Step 1- DNA unwinds解開.Step 2- Once the molecule is separated it copies itself.The new strand of DNA has bases ide

4、ntical to the original.,DNA Replication,,TranscriptionDNA→mRNAIn the nucleusTranslationmRNA→amino acidsIn the ribosomes,Gene expression,Transcription轉錄& Translation翻譯,Genetic code,The flow of information from g

5、ene to protein is based on 64 (4³) codons.A codon consists a three-base sequence that stands for one amino acid or starts or stops synthesis of a protein.,TACGCACATTTACGTACGCGGATGCCGCGACTATGATCACATAGACATGCTGTCAGCT

6、CTAGTAGACTAGCTGACTCGACTAGCATGATCGATCAGCTACATGCTAGCACACYCGTACATCGATCCTGACATCGACCTGCTCGTACATGCTACTAGCTACTGACTCATGATCCAGATCACTGAAACCCTAGATCGGGTACCTATTACAGTACGATCATCCGATCAGATCATGCTAGTACATCGATCGATACTGCTACTGATCTAGCTCAATCAAACTC

7、TTTTTGCATCATGATACTAGACTAGCTGACTGATCATGACTCTGATCCCGTAGATCGGGTACCTATTACAGTACGATCATCCGATCAGATCATGCTAGTACATCGATCGATACTGCTACTGATCTAGCTCAATCAAACTCTTTTTGCATCATGATACTAGACTAGCTGACTGATCATGACTCTGATCCCGTAGATCGGGTACCTATTACAGTACGATCAT

8、CCGATCAGATCATGCTAGTACATCGATCGATACT,Human Genome基因組3.2 billion bases,,Genetic jargon行話,Gene Mutations突變,Gene mutationSubstitutionDeletion (Frame shift mutation)Insertion (Frame shift mutation),Substitution,Insertions/

9、Deletions,Genetic disorders,Single gene disorders Autosomal Dominant Autosomal RecessiveX-linked DominantX-linked RecessiveY-linked disorder Multifactorial and polygenic disorders,Autosomal Dominant,50% c

10、hance,Achondroplasia,It is the most common form of short-limb dwarfism,Mutations of the FGFR3 gene on chromosome 4,FGFR3 protein is concentrated in the cartilage and the central nervous system, so mutations in the FGFR3

11、gene predominantly affect these parts of the body.,Autosomal Recessive,25% chance,Sickle Cell Anemia,sickle cell gene on chromosome 11,Characteristic features include anemia, repeated infections, and periodic episodes of

12、 pain.,It is a group of genetic disorders caused by sickle hemoglobin.,X-linked Dominant,Aicardi Syndrome,? A rare congenital disorder characterised by absence of

13、 the corpus callosum, retinal abnormalities, and seizures (infantile spasms),Aicardi gene located at Xp22,X-linked Recessive,Color Blindness,Sex-Linked Traits: Normal Color Vision: A: 29,  B: 45,&#

14、160; C: --,  D: 26   Red-Green Color-Blind: A: 70,  B: --,  C: 5,  D: --  Red Color-blind: A: 70,  B: --,  C: 5,  D: 6  Green Color-Blind: A: 70,

15、0; B: --,  C: 5,  D: 2,Y-linked disorder,Affects male only.,Infertility,complete inability to produce sperm,Azoospermia精子缺乏,Multifactorial & Polygenic Disorders,? Combination of environmental factors and

16、 mutations in multiple genes (polygenic)? Multifactorial ? Example: Heart disease High blood pressure Diabetes Cancer, Obesity? Polygenic ? Example: Breast cancer susceptibility genes found on chromoso

17、mes 6, 11, 13, 14,15, 17 and 22.,2024/3/18,Genetic Engineering,Isolation of target genesRecombinationTransformation Identification,Producing insulin with bacteria,Genetically-engineering bacteria,Polymerase Chain Reac

18、tion (PCR),To amplify擴大 a single or a few copies of a piece of DNA across several orders of magnitude數(shù)量級, generating thousands to millions of copies of a particular DNA sequence,Thermal cycler,Kary Mullis Nobel Prize in

19、 chemistry, 1993,PCR Reaction ComponentsDNA template (gene you want to copy)primers specific for the templatefree nucleotides (dNTPs)DNA polymerase,PCR procedures,Denaturation變性 94–98 ℃ for 20–30 seconds,Anneal

20、ing熱處理 50-65℃ for 20–40 seconds,Extension擴展 70-75 ℃ for 60 seconds,,Step3Extension, 72 ℃,Gel Electrophoresis,To identify whether PCR generated the expected target genes,genetics replication deoxyribonucleic acid (

21、DNA) chromosome nucleotidebase pair complementary genetic code codon amino acid polymerase template transcription,Key Words 1,14.translation polypeptide ribosome mutation recombination transforma