《医学遗传学》7年制课件Molecular Basis of Genetics.ppt

3．Gene Expression 3.1．Transcription Coding strand (sense strand) Anticoding strand (antisense strand) 3．Gene Expression 3.1．Transcription Methylated cap (m7?G) 3．Gene Expression 3.1．Transcription Methylated cap (m7?G) Splicing Ploy(A) tail 3．Gene Expression 3.2．RNA editing Alteration in the nucleotide sequence of messenger RNA after it has been transcribed from DNA, changing the nature of its protein product from what was encoded. 3．Gene Expression 3.3．Translation The synthesis of a polypeptide using messenger RNA as a template. G GGG GAG GCG GUG A GGA Glu GAA GCA GUA C GGC GAC GCC GUC U Gly GGU Asp GAU Ala GCU Val GUU G G AGG AAG ACG Met AUG A Arg AGA Lys AAA ACA AUA C AGC AAC ACC AUC U Ser AGU Asn AAU Thr ACU Ile AUU A G CGG CAG CCG CUG A CGA Gln CAA CCA CUA C CGC CAC CCC CUC U Arg CGU His CAU Pro CCU Leu CUU C G Trp UGG UAG UCG UUG A Stop UGA Stop UAA UCA Leu UUA C UGC UAC UCC UUC Third letter U Cys UGU Tyr UAU Ser UCU Phe UUU U First letter G A C U Second letter 3．Gene Expression 3.4．Central dagma of eukaryote DNA RT RNA transcription Protein translation replication replication Information flow 4．Genetic Imprinting The genetic phenomenon involved in the control of a small proportion of genes in the genome, where the allele that is expressed is determined solely on which parent contributes it. Genomic imprinting Parental imprinting 4．Genetic Imprinting The genetic phenomenon involved in the control of a small proportion of genes in the genome, where the allele that is expressed is determined solely on which parent contributes it. Imprinted region Molecular Basis of Genetics Medical Genetics Emphasis Structure of Eukaryotic Gene Genetic imprinting Dynamic mutation bp P A T G C Deoxyribose 1．Structure of DNA Adenine(A) Guanine(G) Cytosine(C) Thymine(T) 1．Structure of DNA 1．Structure of DNA Genome 1．Structure of DNA Winkler, 1920 A genome is the complete collection of hereditary information for an individual organism. Genome Unique sequence Repetitive sequen