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
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