Hs

• Genome


  An organism’s complete set of DNA, including all of its genes

  
• Each genome contains all of the information needed to build and maintain that organism

  
• Genetic make-up of organism lies in the DNA sequences

  
• If two individuals differ, then their DNA sequences will also vary, at least at some places if not all
• In humans, a copy of the entire genome—more than 3 billion DNA base pairs—is contained in all cells that have a nucleus

  
• Genomics


  The study of genes and their function
• Goals of Human Genome Project

  • Identify all the approximately 20,000-25,000 genes in human DNA
  • Determine the sequences of the 3 billion chemical base pairs that make up human DNA
  • Store this information in databases
  • Improve tools for data analysis
  • Transfer related technologies to other sectors
  • Address the ethical, legal, and social issues (ELSI) that may arise from the project

  
• The scientific project which deals with the study of base sequences of DNA molecules of complete set of chromosomes is called the Human Genome Project

  
• Human Genome Project was called a mega project

  
• Reasons Human Genome Project was called a mega project

  • Involved a lot of money
  • Most advanced technologies
  • Numerous computers
  • Many scientists
  • A long span of time

  
• HGP was a 13 year old project by U.S. Department of Energy and the National Institute of Health
• HGP was launched


  1990
• HGP was completed


  2003
• Bioinformatics


  A new area in biology closely associated with HGP
• Salient features of HGP

  • The human genome contains 3164.7 million nucleotide bases
  • The average gene consists of 3000 bases
  • The largest known human gene being dystrophin at 2.4 million bases
  • The total number of genes is estimated at 30,000
  • 9 percent nucleotide bases are exactly the same in all people
  • The functions are unknown for over 50 percent of discovered genes
  • Less than 2 percent of the genome codes for proteins
  • Repeated sequences make up a very large portion of the human genome

  
• Methodologies of HGP


  • Expressed sequence tags (ESTs)
  • Sequence annotation
• Procedure for DNA fingerprinting

  1. Isolation of DNA

  2. Digestion of DNA by restriction endonuclease

  3. Separation of DNA fragments by electrophoresis

  4. Transferring of separated DNA fragments to synthetic membranes

  5. Hybridisation using VNTR probes

  6. Detection of hybridised DNA fragments by autoradiography

  
• DNA fingerprinting is a laboratory technique used to establish a link between biological evidence and a suspect in a criminal investigation
• DNA fingerprinting


  A method of isolating and identifying variable elements within the base-pair sequence of DNA
• The technique of DNA fingerprinting was developed in 1984 by British geneticist Alec Jeffreys
• Satellite DNA


  DNA sequences that contain highly repetitive DNA
• DNA polymorphism


  A DNA sequence variation that is not associated with any observable phenotypic variation
• Sources of materials for DNA fingerprinting

  • Blood sample
  • Hair
  • Nails
  • Skin
  • Semen
  • Saliva
• Rice has the smallest genome amongst the major cereals
• The rice genome is about 389 mb, 370.7 mb has been sequenced, 18.1 mb unsequenced
• The rice genome has about 40,000 genes (37,344 coding genes)
• One gene can be found every 9.9 kb, a lower density than that observed in Arabidopsis
• DNA fingerprinting applications also prove useful in finding the parents of unclaimed babies by conducting paternity tests
• Applications of DNA fingerprinting

  • Identification of criminals
  • Problem of paternity
  • Paleontology
  • Archaeology
  • Biological classification
  • Evolutionary change and relationships