Pol olymo ymorp rphisms hisms and nd RF RFLPs By Am Amr r - PowerPoint PPT Presentation

Pol olymo ymorp rphisms hisms and nd RF RFLPs By Am Amr r S. Mo Moustafa, stafa, M. M.D. D.; ; Ph Ph.D. D. As Assista stant nt Pro rof. f. & C Consultan ltant, Medical cal Bioch chemi mistr stry y Dept. Colle lege ge of M f Medicin cine, KSU SU am amrs rsm@ho @hotmail. tmail.co com

Rev evision: ision: Pro roka karyotic ryotic Ge Gene ne Ex Expre ression ssion an and d Reco combinant mbinant Pro rotein in Pro rodu ductio ction n • Production of Recombinant DNA • Bacterial transformation • Screening for target clone • Prokaryotic gene expression protocol • Uses of recombinant proteins

Obj bjec ecti tive ves: s: Po Poly lymor orphi hisms ms and nd RF RFLPs Ps  Polymorphisms Vs mutations  RFLPs  Single nucleotide polymorphisms (SNPs)  Variable number tandem repeat (VNTR)  Medical applications

Bac ackgr kground ound inf nform ormation: ation: De Defi finitions nitions Alleles: Different forms of the same gene on a specific locus Genotype: The set of alleles that make up the genetic constitution Phenotype: The observable expression of a genotype

Po Polymo lymorphi rphisms sms Vs Vs Mu Mutation tations Genetic polymorphisms: Common alleles > 1% Mutations: Rare alleles < 1%

Po Polymo lymorphisms: rphisms: Sites tes Inter-genes or intronic: Detected by DNA sequence analysis Gene coding sequences: Different protein variants Distinct phenotypes (may be) DNA regulatory regions: may affect phenotypes

Po Polymo lymorphisms: rphisms: De Detection tection At At DN DNA le A level vel  DNA sequence analysis  Restriction fragment length polymorphisms (RFLPs): Inherited variations in DNA sequences Restriction enzyme Different sizes of DNA fragments

RFL RFLPs Ps: : Ca Caus uses es Single nucleotide polymorphisms (SNPs): Gain or loss of a restriction site more frequent than VNTR Variable number tandem repeat (VNTR): Alteration of number of nucleotides between restriction sites: 2 unrelated individuals: different pattern Identical twins: identical pattern

SNP NP an and VN VNTR TR

RF RFLP LPs: s: VN VNTR TR For each person a pair of homologous chromosomes is shown

RF RFLP LPs: s: Med edical cal application ications  Mapping a gene to a particular region of a chromosome  Tissue typing for organ transplantation  Paternity testing and forensic applications  Prenatal diagnosis of genetic diseases

RF RFLP LPs: s: Pr Prenatal natal Di Diag agnosis nosis of f sickle ckle cell l an anemi mia a - 1

RFL FLPs: Ps: Pr Prenat natal al Di Diag agnosi nosis s of f sickle ckle cell l an anemi mia a - 2