* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download group_presentation
Polyadenylation wikipedia , lookup
Transposable element wikipedia , lookup
Genetic engineering wikipedia , lookup
Nucleic acid tertiary structure wikipedia , lookup
Gene nomenclature wikipedia , lookup
Epigenetics of human development wikipedia , lookup
Site-specific recombinase technology wikipedia , lookup
Genetic code wikipedia , lookup
Deoxyribozyme wikipedia , lookup
Gene therapy wikipedia , lookup
History of RNA biology wikipedia , lookup
RNA interference wikipedia , lookup
Nutriepigenomics wikipedia , lookup
Genome (book) wikipedia , lookup
Point mutation wikipedia , lookup
Microevolution wikipedia , lookup
Gene therapy of the human retina wikipedia , lookup
Public health genomics wikipedia , lookup
Primary transcript wikipedia , lookup
Helitron (biology) wikipedia , lookup
Epitranscriptome wikipedia , lookup
Non-coding RNA wikipedia , lookup
Therapeutic gene modulation wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
Designer baby wikipedia , lookup
Neuronal ceroid lipofuscinosis wikipedia , lookup
RNA silencing wikipedia , lookup
Epigenetics of neurodegenerative diseases wikipedia , lookup
QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture. Trinucleotide Repeats by: Guy, Hannah, Julien and Max Trinucleotide Repeats •Within our DNA, it is very common to have a triplet base repeat in which the same triplets are repeated more than once in a strand. •If the number of repeats is too large, it can trigger a problem that results QuickTime™ in an identifiable disease. and a TIFF (Uncompressed) decompressor •If the repeat is present intoasee gene, an expansion of are needed this picture. the repeat results in a defective gene product and often disease. •Many inherited diseases are the result of a single difference in the genetic code for a particular protein. As a result of that difference, either a protein is not made at all, made in inadequate amounts, or made in a defective form. Trinucleotide Repeats Continued • The most common repeat is CAG which codes for Glutamine. 8 of the 14 trinucleotide repeat diseases possess this repeat and are called polyglutamine, and the other 6 who don’t have this repeat, are called non- polyglutamine. • Trinucleotide repeat disorders generally show genetic anticipation, where their severity increases QuickTime™ and a with each successive generation that inherits TIFF (Uncompressed) decompressor them. are needed to see this picture. • Trinucleotide repeat disorders are the result of extensive duplication of a single codon. In fact, the cause is trinucleotide expansion up to a repeat number above a certain threshold level. • Expansion of trinucleotide repeats is now recognized as a major cause of neurological disease. HUNTINGTONS DISEASE • • • 1 out of the 14 documented trinucleotide repeat disorders; 1 of several polyglutamine diseases The trinucleotide repeat in Huntington’s disease is the CAG repeat. Patients with the QuickTime™ and a CAG repeat in the Huntingtin TIFF (Uncompressed) decompressor gene who have Huntington’s QuickTime™ and a are needed to see this picture. TIFF (Uncompressed) decompressor disease have repeat lengths are needed to see this picture. between 39-70 repeats. A normal chromosome only has 9 to 30 CAG's. This repetition produces an altered form of the Htt protein, mutant Huntingtin which results in neuronal cell death in select areas of the brain and is a terminal illness. HUNTINGTONS CONT. • Since the Huntingtin protein is found in most neurons throughout the brain, these neurons become infected and start a process of cell death. Once enough cells die within the brain, Huntington’s disease occurs. • Symptoms: Loss of facial expression (called "masks in movement") or exaggerated facial gestures, ability to sit or stand stably, speech, chewing and swallowing. Eventually, it leads to an inability to walk, talk and eat. Death occurs generally 10- 30 years after the first sign of symptoms. • Prevalence:1 in every 10,000 Americans have Huntington’s disease, with about 150,000 at risk of inheriting it from a parent. • Currently, there is no cure, but symptoms are managed by using medications. Myotonic Dystrophy Myotonic Dystrophy is a severe inherent form of muscular QuickTime™ QuickTime™ and and a a deficiency where weakness and TIFF (Uncompressed) (Uncompressed) decompressor decompressor TIFF are are needed needed to to see see this this picture. picture. decomposition of the muscle occurs. This is often characterized by mental retardation or the difficulty of movement of limbs. GENE SILENCING Discovered • Gene silencing is the method used to “silence” or block out of specific sequences of DNA or RNA, used to help prevent or treat diseases and also QuickTime™ and a serves otherTIFF purposes (Uncompressed) decompressor needed to see this picture. • In 2003 Andy are Fire of the Carnegie Institute of Washington and Craig Mello of the University of Massachusetts realized they could prevent a gene from being expressed by injecting or feeding the animal (nematode worms in this case) a double stranded RNA that corresponds to the worm’s DNA gene they are trying to silence GENE SILENCING Process 4 Steps • Step 1: scientist insert a double-stranded RNA into a cell, one of the strands of that RNA contains the identical sequence of bases to the gene that the scientist wants to silence (for now we will call it code X) QuickTime™ and a TIFF (Uncompressed) decompressor • Step 2: because are cells should only single-stranded RNA the needed to see thishave picture. cell identifies the double-stranded RNA as an intruder CELL Double stranded RNA Identical to desired sequence GENE SILENCING Process Cont. • Step 3: it is the Dicer enzyme’s job to get rid of this intruder RNA strand and then goes after the double-stranded RNA, however, when it does this, because one of the stands in the doublestranded RNA codes for the gene that is desired to be silent (code X), and there is an identical code for that same gene in QuickTime™ and a the cell’s original (also code X), the Dicer enzyme TIFFmRNA (Uncompressed) decompressor are needed to see this picture. recognizes both code Xs as intruders and destroys the doublestranded RNA along with the code X portion of the cell’s original mRNA • Step 4: because the Dice enzyme destroyed the code X in the cell’s mRNA code X will no longer be translated through protein synthesis and will not code to make the undesired protein, and therefore it will never be expressed FRIEDREICHS ATAXIA • It is an inherited disease that causes damage to your nervous system that can later cause speech problems or heart disease. • Can result in the loss of nerve tissue in the spinal cord. The spinal cord will become thinner and cause you to be clumsy and have little balance. • Can also result in the loss of nerves that control the movement of your arms and legs. • Friedreich’s Ataxia is an autosomal recessive disease caused by the mutation in gene X25. QuickTime™ and a • Some symptoms include: TIFF (Uncompressed) decompressor are needed to see this picture. – o Muscle weakness – o Loss of coordination – o Hearing loss – o Slurred speech – o Scoliosis – o Extreme heart conditions • Some people suffering from Friedreich’s Ataxia may require surgery, mainly for the heart and spinal cord. For the spinal cord, a metal rod may be places in the spine to prevent scoliosis. • Researchers are expecting a drug to come out for Friedreich’s Ataxia around spring 2008.