Chapter 13 Applying Genetics

Selective Breeding Breed only animals with a desired trait Ex: Chihuahua, Dairy Cows, Mr. Johnston Saint Bernard Rescue dog Husky Sled dog German shepherd Service dog

Hybridization Be more disease-resistant Produce more offspring Mixing strains/breeds/species Hybrids may: Be more disease-resistant Produce more offspring Grow faster Be expensive/time-consuming to make

Inbreeding Not what family reunions are meant for Amplifies gene frequency: good or bad Used for creating/maintaining new breeds Is inbreeding evil?

Test Crossing Discover genotype of organism w/ dominant phenotype Breed with homo rec. If any offspring are rec…

Genetic Engineering (13-2) Insert DNA from 1 organism into another (exogenous DNA) Why? To make glowing cats.

Why really? Give beneficial traits to animals Cure genetic disorders Study genes, cell processes Genetically engineered bollworm

Genomes Total DNA in a cell Can be manipulated Add/remove genes

DNA Tech (13-2) Restriction enzymes cut DNA at specific sequences Gel electrophoresis separates pieces by size to make DNA fingerprint Paternity/forensics PCR amplifies DNA We are also able to sequence DNA

Biotechnology (13-3) Transgenic organisms: genetically engineered Add gene from other organism Not hybrids (ex. bear-owl) Commonly use mice, fruit flies, and the roundworm Caenorhabditis elegans

Transgenic Plants Cotton resistant to insects Sweet potato resistant to viruses Rice with more Iron/vitamins Increase yield or nutrition Well intentioned Gene Splicing

Human Genome Project Sequence human’s 3 billion nucleotides Find all ~20,000 genes <2% DNA codes for protein Many noncoding/repeat sections Coding segments usually identical, noncoding vary, used for DNA fingerprint Identify genes (start and stop codons) Allows Genetic tests

DNA Microarrays Converts mRNA from sample to marked cDNA cDNA = gene – introns cDNA sticks to complementary DNA on chip cDNA and chip DNA are single stranded Chip contains possible cDNA sequences of organism Marks show best at most expressed genes on biochip (microarray)

Why microarray? Identifies changes due to disease, SNP’s, etc. SNP? Single nucleotide polymorphism 1 nucleotide added, removed, or switched Accounts for almost all differences in a species Usually has no visible effect (intronic or same amino acid)

Omics Genomics Proteomics Pharmacogenomics Gene therapy Bioinformatics Study of the genome Proteomics Study of protein structure/function in humans Pharmacogenomics Study of genetics impact of drug effects Gene therapy Attempt to fix damaged/faulty DNA Uses a genetically engineered virus to insert DNA Bioinformatics Attempts to catalog & store biological info like genes, alleles…

Cloning Transfer DNA from adult cell to fertilized egg Activate fertilized egg Implant embryo (In Vitro Fertilization) Most clones die/have issues Clones are essentially an identical twin of the parent Clones have no shared knowledge, and can look somewhat different