Transcript Document
New & Allied Areas In this presentation…… Part 1 – New Technologies Part 2 – DNA Fingerprinting Part 3 – Stem Cell Research Part 4 – Cloning Part 5 – Paleontonomics Part 6 – Other Areas Part 1 New Technologies RNA treatment • It will target only a affected DNA unlike the conventional chemotherapy or radiotherapy which destroys cancerous as well as normal cells • This has been tested on a number of uterus cancer patients • They can be used as suicide squad that destroys the genetic material which later converts into tumor Gene therapy • Gene therapy for baldness is in focus • Hemophilia is caused due to certain gene damage/disorder • Blood coagulation/bleeding can be prevented by using drug Recombinant Factor 9 Coagulation, but is very costly and may cost as much as $ 100,000 • Leukemia is caused as the gene divides the cells into two repeatedly • The presence of P53 and RB fractions in the same gene protects from spreading tumors Genetic disorder – a case study Father genes 226 repeats of CGG abnormal Mother genes 16 repeats of CTG normal Baby 1500 repeats of combination (sure death) Child is genetically disordered and will die in few weeks, even second and subsequent children too. Problem could be avoided by gene modification through a process called mitotic disropy or PGD DNA methylation process • Used in molecular diagnostic and pharmacagenomics assays • Involves measuring the differences in DNA methylation between diseased and healthy conditions • Methylation, the phenomenon wherein a methyl group is attached to the cytosine base on DNA, is a major mechanism of control for gene expression siRNA Library • Ambion and Cenix BioScience are codeveloping a library of short interfering RNA (siRNA) for the entire human genome • The companies shall update the siRNA library in step with human genome sequence annotations Cancer detection made easy • Correlogic Systems, a Maryland bioinformatics company developed algorithms that can tease apart the differences in plasma proteins between healthy people and people with cancer • With smarter software and the right set of markers, the company hopes diagnosing difficult-to-catch cancers can be possible with a relatively simple and painless blood test Part 2 DNA Fingerprinting DNA fingerprinting • It appears as a pattern of bands or stripes on X-ray film, that varies for individuals • Only identical twins have the same DNA fingerprint • A child inherits half the bands from mother and half from father • In paternity testing, child’s banding pattern and that of the mother and alleged father. Bands on child’s fingerprint that are not from the mother are obviously from the real father • First case of DNA fingerprinting was introduced in 1986 but first conviction based on this concept was in 1987 Limitations of DNA fingerprinting • Lot of good quality DNA is needed, sometimes not possible as DNA can degrade with time • Insufficient biological evidence at the scene of crime • Genome is unstable and highly sensitive to radiation, even in the offspring of people exposed to it Part 3 Stem Cell Research Stem cell research • Has been banned in many countries and many have remained undecided • It is important to note that during organ transplant the human body immediately rejects organs from bodies whose DNA does not match with it • Stem cells of embryo are giving clues of generating cells and as catalyst for evolution • With this, it will become possible to produce babies and organs in lab Organ development thru stem cells • Work is going on extensively to develop organs like heart, kidney, eye, etc. • Researchers have worked extensively in Japan for development of eyes of frogs successfully • Next target is heart and kidneys Stem cells for heart patients • Stem cells from another organ can be injected into the heart of heart patients. Patients who have undergone as many as seven bye-pass surgeries have responded excellently • They improve the working of the cells to which they are attached • The bone marrow cells could be injected as stem cells into the affected heart • The genes in bone marrow multiplies the white blood cells which is a good sign for patients Part 4 Cloning Cloning • The term “clone” was coined in 1963 by J B S Haldane • Scientists get tadpoles by transfer of cell nuclei from adult frogs in 1975 • Sheep and cattle cloned by nuclear transfer from embryonic cells in 1986 • Dolly, the sheep, is the first ever clone born in Feb 1997, died prematurely • Cloning can leave a number of ethical questions unanswered in the 21st century Cloning • Scientists cloned 50 mice from a single adult mouse in 1998. Also cloned 8 calves from a single adult cow • In 2000, pigs and goats reported cloned from adult cells. Britain becomes the first country to grant a patent for cloned early-stage human embryos • 26 Dec 2002, Clonaid claims to have produced the first human clone, a baby girl called Eve Cloning process • The process of putting nucleus taken from any cell of body into an embryonic/egg cell • This is followed by a charged shock that joins the two (nucleus containing the genetic material and the nucleus in the egg) • Thereafter, cells starts multiplying through cell division, by mitosis, automatically Types of cloning • Human cloning aims to replicate humans. It requires implanting a cloned embryo into a woman’s uterus • Therapeutic cloning aims to develop medical therapies. Cloned embryos are grown only up to 14 days, long enough to harvest their stem cells, which may eventually prove useful in treating diseases including Parkinson’s, leukemia and diabetes Q&A about human cloning • Will my clone be an exact copy of me? – No. It will only have the same genes, but genes are only one component of a person’s identity. Environment is a big influence. Your clone may well have a different IQ, personality, even looks • Are clones unnatural? – No. Identical twins are natural clones. Many organisms reproduce by cloning. What is artificial is the process of cloning. But then so is test tube baby-making • Is cloning healthy? – No. So far, cloned animals suffer from premature ageing Q&A about human cloning • Should cloning be banned? – No. Therapeutic cloning, where single organs and cells are copied, could have major medical benefits. Reproductive cloning, where a whole person is copied, needs regulation. But a ban would only drive the technology underground • Who opposes cloning? – The loudest critics are conservative religious groups and environmentalists. Scientists are divided, but most oppose outright bans • Will cloning ever become widespread? – Probably not. Surveys show most couples prefer mixed genetic offspring. Megalomaniacs, once they realize a clone is likely to be a different person, may drop the idea Scientists feel… • The technique is not safe to be extended to humans • It took 276 failed attempts before Dolly was successfully cloned. And even after her birth, she has been growing old much before her time, showing that when she was born she was not genetically year zero but as old as her donor • So if Eve is a clone, she might be genetically 31 years old – the age of her donor and can therefore face shortened lifetime of suffering and premature aging Moreover, … • In most pregnancies involving clones, the clone has died and the life of the mother has been put at risk • In many cases, the clone has grown abnormally large, often threatening to tear the womb • Also, almost all clone pregnancies spontaneously abort. And, of the small number (less than 1 %) of animal clones that make it to term, most have severe abnormalities and possibly hidden genetic defects • Several cow clones had head deformities and none survived very long Cloning seems to be • Cheap • Easy • Impossible to ban Part 5 Paleontonomics Fossil recognition • The mitochondrial DNA can be taken from fossils and it can survive even after many centuries • But no guarantee can be given of assured retrieval • Mitochondrial DNA is built with 50 percent DNA taken from father and remaining from the mother • Identity of an individual cannot be established using DNA sequences generated from it but it can be said whether or not it belongs to a particular family Draft sequence for Tyrannosaurus rex genome • The T. rex International Paleontonomics Experiment (TrIPE), based at Sanger Institute, Cambridge UK announced that it had assembled and deposited into public databases – the genetic blueprint for the most important of the dinosaurs used in genetics today • TrIPE used the newly developed Glycosylated Endonuclease Sequencing Strategy (GESS) technique • The consortium is seeking world wide patent rights to the sequence of any organisms sequenced by the technique • The full T. rex sequence is available at Ensembl Men are like mice • 1200 new human genes have been identified by deciphering the DNA code of laboratory mouse • Mice and human share the same genes for blood pressure, temperature regulation, bone manufacture, cell division, tissue growth and so on • Of a sample of 700 genes so far linked to human disease, mice share 90 percent • Laboratory mice are answering questions about HIV, obesity, osteoporosis, Down’s syndrome, schizophrenia, diabetes, heart disease, Parkinson’s, breast cancer, malaria and host of other conditions 5 genetics types of man • Scientists studying whole genome study of 52 human groups around the world concluded that people belong to 5 principal groups corresponding to the geographical regions viz., Africa, Europe, Asia, Melanesia and the Americans Part 6 Other Areas Nutrigenomics • Up to 35 percent of cancers are related to dietary habits • Life long diets high in plant foods lower cancer rates • People who eat lots of fruits and vegetables are skinnier • Obesity increases risks of cancers of uterus, gall bladder and possibly colon and prostate • Large weight gain after reaching adulthood is linked to breast cancer • Scientists in China found that people with lowest lung cancer risk were genetically deficient in an enzyme that metabolises certain nutrients in cruciferous vegetables Longevity gene? • Mice lacking a copy of an important metabolism gene live to the human equivalent of a century, according to new research on induced longevity • The gene encodes a protein called insulin-like growth factor (IGF-1) • Mice which had been genetically changed to lack one copy of this gene live on average 26 percent longer than normal counterparts, without any side-effects • One reason for this appears to lie in oxidative stress, an ageing and disease-causing process by which cells are damaged by roving molecules with unpaired electrons Proteomics • It is the study of proteins in cells and tissues in the body • Since cells are constantly responding to their environment, and the proteins are the workhorses of the cell, the proteome changes reflecting the life of the cell • In future, it shall cover metabolomics, transcriptomics, etc. areas Metabolomics • It is the study of chemicals in the body called metabolites • Every human cell contains thousands of these chemicals and each disease leaves a different metabolic fingerprint • A recent experiment at St. George’s Hospital Medical School, London discovered how cancer cells give themselves a turbo-boost to grow faster • Metabolomics will help researchers design new drugs to attach each different disease Transcriptomics • It uses gene ‘chips’ to investigate what the thousands of genes inside cells are doing • It involves large-scale analysis of mRNAs transcribed from active genes to follow when, where and under what conditions genes are expressed (mRNA carries the genetic information for the synthesis of specific proteins)