BIOL 2416 Chapter 1: Genetics: An Introduction

Course Information Lecture Lab Attendance Exams Paper

Introduction to Genetics Genetics = study of heredity. (structural) gene = chunk of meaningful DNA that codes for production of a cellular protein. 4 sub-disciplines: Transmission Genetics (a.k.a. Classical Genetics) Molecular Genetics Population Genetics (a.k.a. Evolutionary Genetics) Quantitative Genetics

Transmission/Classical Genetics Mendelian inheritance Mitosis and meiosis Pedigree analysis Controlled breeding Mutational analysis Cytogenetics (chromosomal alterations) Gene mapping

Molecular Genetics DNA structure and function DNA replication Transcription and translation Control of gene expression Recombinant DNA / Genetic Engineering Genomics DNA mutation Extrachromosomal inheritance

Population/Evolutionary Genetics Deals with 1 or few genes Measure changes in allele frequency within a population over time evolution Measure the effects of DNA mutation, migration, selection, and genetic drift on gene frequencies (allele = gene variant) (population = interbreeding, localized group of individuals of same species) (gene pool = all alleles in a population)

Quantitative Genetics Study of of grayscale traits: Polygenic traits (involves multiple genes) Environmental factors Multifactorial traits (multiple genes and environmental factors) (Involves lots of statistics)

Scientific Method Observation Hypothesis Experimentation Reasonable explanation Experimentation To test hypothesis only 1 testing variable Involves if…then prediction Use control results to troubleshoot repeat REJECT or SUPPORT hypothesis

Scientific Theory Big deal Collection of related hypotheses that have stood the test of time (always supported, never rejected) Details may still be worked out

2 Kinds of Research BASIC: APPLIED: Builds foundation of knowledge (Encyclopedia A-Z) No immediate use in mind APPLIED: Often based on basic research Geared towards specific use Not always concerned with how and why, as long as it works

Model Organism Criteria Easy / cheap to grow and handle Small genome Plentiful offspring from each mating Short life cycle Many marked genetic variations Large genetic history (genetic data bases / genetic mapping data)

Prokaryotic Cells Bacteria unicellular Small and simple Single, circular DNA in nucleoid region No membrane-bound organelles Fig. 1.9 Cutaway diagram of a generalized prokaryotic cell

Eukaryotic Cells All other organisms (including plant and animal cells) Larger and more complex Uni and multicellular With multiple linear chromosomes inside nucleus And other membrane-bound organelles

Common Model Organisms PROKARYOTIC: Escherichia coli EUKARYOTIC: Saccharomyces cerevisiae (unicellular baking yeast) Drosophila melanogaster (fruit fly) Caenorhabditis elegans (nematode worm) Arabidopsis thaliana (mustard weed) Mus musculus (mouse)

Resources for Genetic Research: Genetic Maps Locus/loci Map units/CentiMorgans

Resources for Genetic Research: Genetic Databases http://www.embl.org http://www.ncbi.nlm.nih.gov http://genetests.org http://icomm.ca/geneinfo http://www.rarediseases.org