* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Presentation
Quantitative trait locus wikipedia , lookup
Epigenetics of neurodegenerative diseases wikipedia , lookup
Gene therapy wikipedia , lookup
Cancer epigenetics wikipedia , lookup
Nucleic acid double helix wikipedia , lookup
DNA vaccination wikipedia , lookup
Epigenomics wikipedia , lookup
Nucleic acid analogue wikipedia , lookup
Population genetics wikipedia , lookup
Y chromosome wikipedia , lookup
DNA damage theory of aging wikipedia , lookup
Genealogical DNA test wikipedia , lookup
Genome evolution wikipedia , lookup
Human genome wikipedia , lookup
Frameshift mutation wikipedia , lookup
Molecular cloning wikipedia , lookup
Genetic testing wikipedia , lookup
Genomic library wikipedia , lookup
Oncogenomics wikipedia , lookup
Neocentromere wikipedia , lookup
Medical genetics wikipedia , lookup
DNA supercoil wikipedia , lookup
Public health genomics wikipedia , lookup
Human genetic variation wikipedia , lookup
Nutriepigenomics wikipedia , lookup
Deoxyribozyme wikipedia , lookup
No-SCAR (Scarless Cas9 Assisted Recombineering) Genome Editing wikipedia , lookup
Therapeutic gene modulation wikipedia , lookup
Cre-Lox recombination wikipedia , lookup
Extrachromosomal DNA wikipedia , lookup
X-inactivation wikipedia , lookup
Non-coding DNA wikipedia , lookup
Helitron (biology) wikipedia , lookup
Site-specific recombinase technology wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
Genome editing wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Cell-free fetal DNA wikipedia , lookup
Point mutation wikipedia , lookup
Genetic engineering wikipedia , lookup
Designer baby wikipedia , lookup
Genome (book) wikipedia , lookup
Human Heredity and Biotechnology Chapter 11.1 & 11.3 with a scattering from Chapter 13 RECESSIVE GENETIC DISORDERS • may be passed on to children without knowing – because parent can be “carrier” • passed like any recessive trait • heterozygous condition - “carrier” • some recessive genetic disorders include… Cystic Fibrosis Albinism Galactosemia Tay Sachs RECESSIVE GENETIC DISORDERS CYSTIC FIBROSIS (CF) – affects the mucus producing glands, digestive enzymes and sweat glands Caused by a defective gene Effects • excessive mucus production • higher risk of infection and respiratory system is compromised • digestive and respiratory system failure Cure/Treatement • no cure • daily breathing treatments • mucus-thinning drugs • pancreatic enzyme supplements • life expectancy 36.8 years RECESSIVE GENETIC DISORDERS ALBINISM – partial or total lack of pigment (melanin) in hair, skin and eyes Cause – defective gene; do not produce normal amounts of pigment (melanin) Effects - skin susceptible to UV damage - higher risk of skin cancer and eye damage - occurs in humans and other mammals Cure/Treatment - No cure - Protect eyes and skin from sun RECESSIVE GENETIC DISORDERS GALACTOSEMIA – an inability to digest galactose (milk sugar) Caused by – absence of a gene that codes for the enzyme that breaks down galactose Effects • enlarged liver and kidney failure • galactose builds up in the cells and becomes toxic • usually causes no symptoms at birth • if not detected immediately results in liver disease, mental retardation and death Cure/Treatment • no cure • children diagnosed early can have a normal, healthy life • treatment is the restriction of galactose and lactose from the diet RECESSIVE GENETIC DISORDERS TAY-SACHS DISEASE – a build up of fatty deposits in the brain - only affects people of Jewish descent Caused by – absence of an enzyme that breaks down fatty substances Effects • inability to break down fatty acids • fatty acids build up in the brain • brain cells deteriorate • mental capacity is diminished Cure/Treatment • No cure or treatment • Death by age 5 Dominant Genetic Disorders • only need one dominant allele to inherit the disorder • no carriers • some dominant genetic disorders include… Huntington’s Disease Achondroplasia DOMINANT GENETIC DISORDERS HUNTINGTON’S DISEASE results from the genetically programmed degeneration of brain cells Caused by a gene affecting neurological function Effects • symptoms appear between 30 and 50 years of age • degeneration of brain cells (neurons) • loss of intellectual faculties • uncontrollable movements • emotional disturbances Cure/Treatment none woman with Huntington’s Disease at age 48 DOMINANT GENETIC DISORDERS ACHONDROPLASIA – most common form of dwarfism Caused by a mutated gene that affects bone growth Effects • short arms and legs • 75 % of individuals with achondroplasia are born to parents of average size – HOW CAN THIS HAPPEN? Conclusion – occurred because of mutation Cure/Treatment • none • normal life expectancy PEDIGREE chart which shows the inheritance of a trait from one generation to the next Allows geneticists to trace the transmission of a trait through a family. square = male circle = female colored shape = has trait half colored shape = carrier slash = deceased Alexandrina Victoria, born May 1819 British Monarch Queen Victoria was a carrier of hemophilia. She had nine children and passed hemophilia on to several of them. All of her children married into the royal families of various countries of Europe. In this way, all of the Royal Families of Europe inherited the gene for hemophilia. How many generations are represented? How many males? afflicted males? normal males? How many females? afflicted females? normal females? Any carriers? Sex-linked or autosomal trait? Dominant or recessive trait? Any twins? deceased individuals? HUMAN CHROMOSOMES Human somatic cells contain…. 46 individual chromosomes or 23 chromosome pairs Of these 23 pairs… SEX CHROMOSOMES (1 pair) • determine the sex of an individual AUTOSOMES (22 pairs) • do not determine the sex of an individual KARYOTYPE is a photomicrograph of the chromosomes in a dividing cell chromosomes are grouped and placed into pairs female - 46 XX male - 46 XY Telomeres protective caps on ends on chromosomes made of protein and DNA may play a role in cancer and aging Mutations What is a mutation? a change in the DNA or a change in a gene – it is interesting that mutations can be helpful, harmful or may have no effect mutations – are a source of genetic variation in LT Mutations What causes a mutation? a mutagen…. A mutagen is….anything that may cause a change in the DNA Some mutagens are viruses, chemicals, toxins, UV light,…. Mutations can also happen as a result of the DNA being copied incorrectly Types of Mutations 1. Somatic cell mutations: affect body cells will affect individual, but not offspring 2. Germ cell mutations: affect germ cells – what are these? Will affect offspring, but not the individual 3. Lethal mutations Will cause death either before or shortly after birth Chromosome Mutations Deletion – A piece of a chromosome is lost Inversion – A piece of a chromosome breaks off, flips over, and reattaches Translocation – A piece of a chromosome breaks off and attaches to another chromosome Nondisjunction – Homologues do not separate properly during cell division loss of a portion of a chromosome Inversion – a section of a chromosome breaks off, flips over and reattaches Translocation – a portion of a chromosome detaches and reattaches to a nonhomologous chromosome Let’s Practice – What type of mutation? NONDISJUNCTION - may arise when chromosomes don’t separate properly during CELL DIVISION … CAN OCCUR IN mitosis or meiosis nondisjunction means “not coming apart” Nondisjunction in Meiosis…can lead to … monosomy (45) – missing a chromosome of a pair (having only 1 chromosome of the pair) trisomy (47) – having an extra chromosome in a pair (having 3 chromosomes in the pair) Conditions resulting from Nondisjunction • Down’s Syndrome • Turner’s Syndrome • Klinefelter’s Syndrome DOWN SYNDROME (also called trisomy 21) male or female having an extra chromosome in pair #21 (3 chromosomes instead of 2) male or female having an extra AUTOSOME 47 XX or 47 XY Nondisjunction on #21 = Trisomy 21 (Down Syndrome) Characteristics of Down Syndrome • • • • • • • • • • almond shaped eyes flat nose bridge large tongue ears are set a bit lower on the head shorter in stature simean crease on the palm of the hand possible congenital heart defects lat feet, sandal toe (large gap between big toe and the next) lower IQ developmental delays TURNER SYNDROME female that is missing a sex chromosome - 45 XO KLINEFELTER SYNDROME male having an extra sex chromosome 47 XXY Fetal (genetic)Testing – pre-pregnancy: DNA testing & genetic counseling – post-pregnancy: PKU testing – during pregnancy: • Amniocentesis • Chorionic Villi Sampling (CVS) • Fetal Blood Sampling Amniocentesis - a small amount of amniotic fluid (containing fetal tissues and cells) is extracted from the amniotic sac surrounding the developing fetus - the DNA is examined for genetic abnormalities Chorionic Villi Sampling (CVS) - the removal of a small piece of the placenta (chorionic villi) during early pregnancy to screen for genetic defects – the placenta has the same genetic makeup as the fetus Fetal Blood Sampling(FBS) - the collection of fetal blood from the umbilical cord or fetus – the blood is tested genetic defects or other abnormalities HUMAN GENOME PROJECT Begun in 1990, it was an attempt to sequence all of the human DNA. Genome = an organism’s DNA Mapping of the human genome completed in 2003. DNA fingerprinting or DNA profiling • A technique for analyzing and comparing DNA from separate sources • Used to identify criminal suspects, determine paternity or the identity of unknown persons • DNA samples are taken from hair, blood, semen, or other biological materials • No two people, except identical twins, have exactly the same DNA According to the DNA fingerprint above, who are the parents of the child? A (A+B) B (C+D) C (E+F) D (G+H) DNA fingerprints of 3 people created using 7 different DNA probes. What do persons 1 and 2 2 and 3 1 and 3 share in common? GENE THERAPY process in which an absent or faulty gene is replaced by a normal, working gene various approaches have been taken… – Bone marrow removed, modified in the laboratory and placed back in the body – Modified viruses have been used to carry replacement genes into the body – Inhalation of genetically engineered viruses containing “good” genes has been attempted up to this point, gene therapy has not been very successful Manipulating DNA… • Today, we have expanded our use of genetic information and we are able to use techniques for manipulating (modifying) DNA. We can…. • extract DNA from cells, • cut it into small pieces, • identify the genes and sequences in DNA • make copies Cell Transformation…. process by which a cell takes in DNA from an outside source • the external DNA may become part of the cell’s DNA Recombinant DNA – taking DNA from one organism and combining it with another organism • we have inserted the genes for human insulin and human growth hormone into bacteria Transgenic Organism… an organism containing genes from another organism bacterium containing recombinant DNA cow containing genes for producing human milk proteins Cloning… process of producing an identical copy of an organism • we have successfully cloned frogs, salamanders, mice, sheep and other organisms DOLLY What is genetic engineering? it is simply…. genetic modification Throughout the ages, man has applied his knowledge of genetics to the world around him – especially to plants and animals. Selective Breeding… aka Artificial Selection is the process of breeding animals or plants with desired characteristics • man has used selective breeding to develop plants and animals with “desirable traits” • nearly all domestic animals – dogs, cats, horses, and most crop plants have been produced by selective breeding Selective Breeding…of plants Selective Breeding…of animals Selective Breeding… Can involve… • Hybridization • Inbreeding Hybridization… crossing dissimilar individuals to bring together the best traits of both organisms hybrids (produced by such crosses) are often healthier and hardier than either of the parents Hybridization … ZEDONK – cross between a zebra and a donkey Hybridization LIGER – cross between a male lion and a female tiger Hybridization Tigon – cross between a female lion and a male tiger Hybridization … male DONKEY and female HORSE = MULE Offspring (mules) are almost always sterile. The mule has greater endurance, is stronger and less excitable than a horse. Inbreeding…continued breeding of individuals with similar characteristics - used to maintain characteristics in a breed Inbreeding… Selective breeding often limits variation…..is this good? Scientists are also interested in preserving the genetic diversity in organisms. WHY is it important to maintain diversity/variation ? How can genetic diversity/variation occur… 1. by inducing mutations (using chemicals or radiation) mutation = a change in the DNA 2. polyploidy – having extra sets of chromosomes – often results in more vigor or increased size 3. genetic recombination as a result of … * crossing over during prophase I of meiosis * sexual reproduction - union of 2 haploid gametes