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

Pol

• lymo

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
• Screening for target clone
• Prokaryotic gene expression protocol
• Bacterial transformation
• Uses of recombinant proteins

• Polymorphisms Vs mutations
• RFLPs
• Single nucleotide polymorphisms (SNPs)
• Variable number tandem repeat (VNTR)
• Medical applications

Obj bjec ecti tive ves: s: Po Poly lymor

• rphi

hisms ms and nd RF RFLPs Ps

Bac ackgr kground

• und inf

nform

• rmation:

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

Inherited variations in DNA sequences Different sizes of DNA fragments Restriction enzyme

• Restriction fragment length polymorphisms

(RFLPs):

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
• f 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