Lesson 2.4 Processes Involved in Genetic engineering Selective breeding the primary method for improvement of Ph crops (rice, corn, cabbage, and sugarcane) employed in the domestication of gray wolves to dogs -----------------------------------------------------------------------------------------------------------Traits such as resistance diseases cannot be easily acquired through classical breeding methods. There are cases wherein an organism possessing a desirable trait is reproductively incompatible to an organism needing that trait. -----------------------------------------------------------------------------------------------------------Genetic Engineering involves direct manipulation of genes of organisms in laboratory for them to express the desired traits. nature is to manipulate the genes add, delete, underexpress, overexpress genes help in medicine, agriculture, pharmaceutical GMO ( Genetically modified organism) product of genetic engineering Recombinant DNA technology (RDNA) the primary technique used in the genetic engineering of organisms. back then it is called as chimera -- hybrid Macedonian Academy of Science and Arts devoted their resources to establish a genetic engineering facility HISTORY 1972: Stanley Cohen and Herbert Boyer » introduced plasmid segment into the plasmid of another bacterium Plasmid --- circular DNA molecules found in cytoplasm of bacterial cells » with their attempt to perform recombinant DNA technology, Escherichia coli became the first transgenic organism Transgenic organism --- transfer DNA molecule to another organism 1974: Rudolf Jaenisch » successfully created the first transgenic animal - a mouse » for example, we have a bioluminescent jellyfish and then we get its protein to transfer it to a mouse == glow in the dark mouse » insert DNA from another organism to the nucleus of a fertilize mouse egg ; it matures and acquire the desirable trait » initial problem he noticed that the child of genetically engineered mouse do not possess the trait 1977: Genentech » the company was able to produce somatostatin, a human protein, through GM E. coli. » E. coli helped humans for we can already buy steroid (insulin) (gm e. coli ) in pharmacies. 1983: Richard Flavell, Mary Dell-Chilton, and Michael Bevan » successfully created the first transgenic crop - a tobacco » it is resistant to herbicide, pest resistance Principles of rDNA Technology 1. DNA as the blueprint of life » gene - source of genetic engineering 2. Proteins as phenotypic determiners » gene can be transferred into proteins and will serve as phenotypic determiners 3. Identification of a gene of interest » identify the desirable trait, the trait you want from an organism 4. Identification of a host organism » identify which organism we'll be using, if it is compatible 5. Introduction of foreign genes » the transfer of genes from one organism to another Example: Normal Corn - infestations lead to major crop damage Bt Corn - use of Bt toxin gene from Bacillus thuringiensis makes corn resistant against corn borers i. Bt Toxin (cry1AB) from bacillus thuringiensis help to eliminate and avoid pests insecticides, pesticides produces cry protein that can cut holes into the gut of the corn borers ii. PROCESS OF GENETIC ENGINEERING iii. A. Identification of Gene of Interest » know the desirable traits B. Isolation of Gene of Interest » separation » restriction enzymes - responsible in the creation of cleavage or cut into specific sequence of DNA - restriction endonuclease - isolate protein from bacteria - (in e. coli) can recognize and cut the sequences: 3'CTTAAG 5'GAATTC » Werner Arber - pioneered the study of the restriction enzymes in bacterial cells - first to study restriction enzymes » Hamilton Smith and Daniel Nathans - first to discover restriction enzymes - elucidated the ability of restriction endonuclease to cut DNA at specific sites - they suggested that restriction enzymes are like our immune system for they don't allow foreign bacteria to enter our body, if ever they cut their DNA molecules C. Introduction of Gene of Interest Methods of Introducing Gene of Interest Electroporation » use of electric impulses to create temporary pores in our cell » where foreign genes can enter and go out Microprojectile bombardment » used small gold or tungsten coated with DNA that is shotted in our cell with the use of biolistic device called gene gun Agrobacterium tumefaciens-mediated transformation » causes crown tumors in plants » an important property used in the genetic engineering of crops for it duplicate or replicate automatically already » cut DNA using restriction enzyme --- recombination --introduced to corn cells -regeneration of plant --- corn plant with mechanism of crow ball formation » an important tool in plant biotechnology due to its natural ability to transfer DNA in the genome of plants Lesson 3.1 Earth's Timeline and Emergence of Life Earth only planet known to support life has been around 3.7 billion years (estimated using geologic time scale) Geologic Time Scale system of dating the history of Earth in a chronological manner using geological data (fossils) reflects the entire geological history of our planet divided into eons, eras, periods, and epochs EONS Eothems refers to the greatest expanse of time has longest duration Phanerozoic Eon (542 MYA) » means visible life that was constructed through rock units that bear abundant fossils » formation of rock units, fossils » Earth gradually assume its present configuration and physical features due to emergence of continental drifting » mountain building, continental distinction » Paleozoic era ↬ Age of Invertebrates ↬ presence of fossils with backbone ↬ Cambrian - first fish - first chordates (animal with backbone) - we are under Chordata since we have backbone ↬ Ordovician - major diversification of animal life ↬ Silurian - first vascular plants ↬ Devonian - first amphibians - fish diversity ↬ Carboniferous - first reptiles, trees, seed ferns ↬ Permian - major extinction - reptile diversity » Mesozoic era ↬ Age of Reptiles ↬ dinosaurs ↬ Triassic Period - first mammals - first dinosaurs ↬ Jurassic Period - first birds - dinosaurs diversity - archaeopteryx (bird/dinosaur) ↬ Cretaceous Period - extinction of dinosaurs - first primates (Homo habilis, apes) - flowering plants » Cenozoic era ↬ Age of Mammals ↬ Tertiary Period - mammals diversity - mammoth ↬ Quarternary Period - human evolution - up until now Precambrian Eon (4BYA) » represents the period between birth of the planet and the appearance of life forms » Age of Early Life » formation of continent, atmosphere, soft bodied creatures (jellyfish, worms) » Proterozoic ↬ collision of tectonic plates still happen » Archean ↬ no oxygen except in water (H2O) » Hadean ↬ characterized by initial earth formation ↬ stabilization of core through volcanic eruption ↬ occurrence of volcanic eruption; release heat which stabilizes the core ↬ no one lives in land; only under the sea Epochs the shortest subdivision unit in the Earth's geologic time scale characterized by the changes in life forms and may vary from continent to continent Can Old Senators Demand Copious Power Than Junior Congressmen? Tough Question! ----------------------------------------------------------------------------------------------------------Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian, Triassic, Jurassic, Cretaceous, Tertiary, Quaternary Theories regarding the origin of life on Earth 1. Spontaneous Generation Theory » living things came from non-living things (Abiogenesis) » Needham experiment - he boiled a broth - while boiling he sealed it with cork to prevent the entry of microorganisms - after several days, he noticed the growth of bacteria or new rise of organism » disproved by Louis Pasteur - he also boiled a broth - he also sealed it - after several days, there is no growth of bacteria or new rise of organism - only when he remove the cover, bacterial growth happened » still happens but not a good theory for the origin of life 2. Theory of Panspermia » exogenesis » suggest that building blocks of life came from another planet » example: comets with living cells fall to earth 3. Primordial Soup Theory » widely accepted theory up to this day » suggest that life started (from nonliving organism) in a primordial soup of organic molecules » proved using the " ELECTRICAL DISCHARGE EXPERIMENT " by Stanly Miller and Harold Urey - sea is composed of H2O, Ammonia, Methane and Hydrogen - heat under serves as the sun - electrical sparks/electrode as lightning - heat result to chemical reaction which formed new organic molecule - at first we only have H2O, ammonia, methane and hydrogen, due to exposure to heat and lightning, it causes chemical reaction resulting to formation of new organic molecule, amino acid (glycine, alanine and aspartic acid) - have environmental factor from nonliving to living » tries to explain how catalysts for nonliving things became living cells Early Evidence of Life on Earth a. Stromatolite fossils layered columns of sedimentary rocks form through the growth of cyanobacteria (single cell that can photosynthesize) collected from various samples of metasedimentary rocks in western Greenland aged 3.7 billion years old b. Microbial Mat (primitive microbial colony) 2015, fossils of it that may represent potential biotic life dated 4.1 billion-year-old were collected in Western Australia found in hydrothermal vents (found in volcanoes under the sea) Write the word true if the given statement is correct and false if otherwise. 1. Abiogenesis states that living organisms originate from preexisting living organisms. FALSE 2. First life forms are believed to have emerged 3.7 billion years ago. TRUE 3. The spontaneous generation theory is still considered as a valid theory even today. FALSE (not valid but still happen) Lesson 4.1 Artificial and Natural Selection Population group of individuals that belong to a species lives in an area and interbreed with one another to form offspring when we talk about population, there is evolution Evolution the change over time there is a process of transformation of species Galapagos finches or Darwin's finches » the ancestor, known as the founder species, diverged into two lineages » first lineage is Amakihi, beak evolves, became longer to adapt to their environment, for them to eat nectars from flowers » second lineage is Nihos Finch, beak became bulky and big for them to eat hard foods like bones and nuts How can evolution cause changes in population? Evolution may cause the alteration in the genetic materials of individuals in the population For example, our parents can passed down hereditable traits But because of evolution, traits needed in order to survive can be passed down Types of Evolution 1. Natural Selection Natural refers to the process when individual organisms that have favorable traits experience greater fitness and reproduce success than those that do not have the trait. survival of the fittest (who can survive in environmental changes) fitness is important as it refers to the capacity of an organism to survive into an environmental changes Importance » helps organisms to capture food effectively, find habitat, mate, communicate, travel, or escape predators swiftly. » higher chance of survival of the species in the community Changes over time happens overtime have process Mechanisms of evolution under the Changes in Population » Overpopulation - every species tends to produce more individuals than can survive to maturity » Variation - individuals of a population have many characteristics that differ - the more variation within a species, the more likely a specie can survive » Selection - some individuals survive longer and reproduce more than others do - individual with the best trait or adaptation will have the high chance of survival, they will be able to pass it to their child - all good trait remains, and all bad features are removed » Adaptation - traits of those individuals that survive and reproduce will become more common in a population 2. Artificial Selection not natural process of selecting plants or animal individuals for breeding process of selecting plants or animal traits with human intervention without human, there will be no artificial selection developed from our understanding of heritable traits Importance » served as the primary principle behind selective breeding used for producing new varieties of plants and animals » increase chances of achieving desirable traits that could lead to higher production in any plant or animal derived products Happen fast not over time Mechanisms of evolution under the Changes in Population » speciation - identify species » divergence » domestication » hybridization » breed formation - for survival Lesson 4.2 Genetic Mechanisms of Population Change Population genetics field of science that deals with genetic variation in the populations of organisms in the ecosystem deals with the examination and modeling of the spatial and temporal variation in frequencies of genes and alleles in populations deals with the changes in alleles and genotype frequency in the population over space and time Alleles different versions of a gene Genotype pairs of genes responsible for a particular trait genetic makeup Phenotype physical expression of a trait Factors affecting Genetic Structure of Population 1. Mutation » can cause changes in the DNA structure of the organisms » alteration through radiation which cause wrong pairing or genetic engineering » essential for driving evolution of organism » driving force of evolution » Types a. Advantageous mutations - increase the fitness of organisms b. Deleterious mutations - decrease the fitness of organisms c. Neutral mutations - do not impact fitness - have highest frequency because it has the highest possibility to stay in a population 2. Genetic Drift » depend on environment but depend to their random events (by chances) » example: chance of event ay matapakan ang beetles, brown beetle will remain 3. Founder Effect » refers to the loss of variation in population » parent population (many variation), then will have migrating population (less variation); only them can produce offspring » from parent population to having migrating population that will cause loss of variation in population 4. Bottleneck Effect » event when there is an abrupt reduction in population due to environmental problems » there is old and there is new 5. Recombination (crossing over) » happens in meiosis I, prophase I » maternal + paternal = homologous pair of chromosome » next is synapsis, pagsasama, create chiasma/ta
