Tehnologija rekombinantne DNA

Recombinant DNA Technology

• Plant breeding has been used to improve agricultural traits, such as yield and disease resistance, since the beginning of human civilization.

• Traditional breeding methods, like controlled pollination or interbreeding, produce new varieties with desirable properties.

• Modern breeding can use in vitro techniques like tissue culture and mutagenesis.

• Genetic engineering, sometimes called molecular breeding, involves modifying genes in plants.

• Breeders can insert desired traits into plants using molecular biology and genetic engineering.

Genetic Engineering vs. Classical Breeding

• Genetic engineering uses molecular techniques to modify plant traits, creating genetically modified organisms (GMOs).

• Classical breeding focuses on mating organisms with desirable traits, utilizing natural processes like plant life cycles.

Recombinant DNA Technology

• Recombinant DNA technology involves manipulating genes through various techniques.

• Its applications are broad, including medicine, forensic science, pharmaceuticals, and agriculture, primarily for improving livestock and crops.

• DNA recombination naturally occurs during meiosis (crossing over of homologous chromosomes) , fertilization , and mutations or transformations.

Tools Used in Recombinant DNA Technology

• Target DNA (gene of interest)

• Restriction enzymes cut DNA into fragments

• DNA cloning vectors (e.g., plasmids, bacteriophages) carry the target gene into a host cell.

• Host cell (e.g., bacterial cell) allows vector replication.

• Modifying enzymes, like DNA ligase and Taq polymerase, aid in the process.

Restriction Enzymes

• Bacteria use restriction enzymes to defend against bacteriophages.

• They recognize and cut DNA at specific sequences called restriction sites.

• Restriction sites are palindromic DNA sequences.

• Different restriction enzymes recognize different sequences and cleave DNA in specific ways (staggered/blunt).

DNA Cloning Vectors

• Cloning vectors carry foreign DNA into host cells, allowing replication.

• Plasmids, bacteriophages, cosmids, and yeast artificial chromosomes (YACs) are examples.

• Plasmids are small, circular DNA molecules naturally found in bacteria.

• They allow foreign genes to be replicated independently in bacterial cells.

Modifying Enzymes

• DNA ligase joins DNA fragments by creating phosphodiester bonds.

• Taq polymerase replicates DNA segments.

Polymerase Chain Reaction (PCR)

• PCR amplifies DNA fragments in a test tube.

• It produces copies of a specific DNA sequence.

• It involves denaturation, annealing, and extension cycles.

• It utilizes Taq polymerase, primers, free nucleotides, and a thermocycler.

Applications of Recombinant DNA Technology

• Widely applied in fields like agriculture (producing crops with desirable traits), medicine (creating insulin), pharmaceuticals, forensics (DNA profiling).

• Genetically modified microorganisms (e.g., bacteria) produce useful proteins.

Gene Cloning

• Gene cloning isolates, inserts a target gene into a vector, and amplifies the gene in a host cell.

• It follows four stages: target gene isolation, insertion into a vector, introduction into a host, and amplification/screening.

• Two methods to isolate target genes: restriction enzymes or creating complementary DNA (cDNA).

Ova kviz istražuje tehnike rekombinantne DNA i njihov uticaj na uzgoj biljaka. Uključuje poređenje između klasičnog uzgoja i genetskog inženjeringa. Saznajte kako se moderne metode koriste za postizanje željenih osobina kod biljaka.