B5844 - GENETICA GENERALE

Learning outcomes

The general objective is to provide students with the foundations for studying genetics and its biotechnological applications. At the end of the course, the student will understand the fundamental principles of the transmission of traits and the nature and action of genes, and will comprehend the basis of genetic variability—from single nucleotides to chromosomal variants—as well as the complexity of genotype-phenotype relationships. The student will also be able to use the acquired knowledge to solve problems and interpret experimental data.

Course contents

Mendel: Fundamental Principles of Heredity

• Experimental and analytical approach to Mendel’s experiments; monohybrid cross and Mendel’s law of segregation; concepts of gene and allele.

• Dihybrid cross and Mendel’s law of independent assortment; methods for calculating genotypic and phenotypic ratios.

• Statistical analysis of genetic data: probability calculations and chi-square test.

• Inheritance of traits in humans: pedigree analysis.

Cell Division and Chromosome Inheritance

• Overview of the stages of the cell cycle in eukaryotic organisms, the concept of karyotype, and the structure and number of eukaryotic chromosomes; concepts of somatic and germline cells.

• Mitosis and meiosis: chromosome behavior during gamete formation; Mendel’s laws as a consequence of chromosome dynamics during meiosis.

• X-linked inheritance, gene dosage compensation, and sex determination.

• Inheritance of X-linked loci in Drosophila (e.g., white locus); evidence supporting the chromosomal theory of inheritance (Bridges’ nondisjunction experiments).

• Chromosomal sex determination.

• Gene dosage compensation in mammals.

Mendelian Genetics in Humans

• Pedigree analysis, Mendelian segregation models (autosomal dominant, autosomal recessive, X-linked inheritance).

Molecular Function of Alleles

• Molecular nature of alleles.

• Functional consequences of mutations (loss of function, gain of function).

• Concepts of haploinsufficiency and dominant negative effect.

Extensions of Mendelian Genetics

• Modifications of dominance relationships (incomplete dominance, codominance); multiple alleles; ABO blood group system; lethal genes.

• Gene-environment interactions; penetrance and expressivity; sex-influenced traits.

• Multiple genes influencing phenotype: gene interaction; epistasis and modified Mendelian ratios; complementation analysis; genetic heterogeneity.

• Continuous variation and multifactorial inheritance. Explanation of how Mendelian principles can account for continuous variation. Polygenic theory. Multifactorial traits, threshold traits.

Recombination, Linkage, and Genetic Mapping

• Independent assortment and linked genes; recombination as a result of crossing over; genetic maps based on recombination frequency; linkage analysis via test cross.

• Relationship between crossing over and map units; effect of multiple crossovers; three-point test crosses for map construction; coefficient of coincidence and interference; mapping functions; difference between genetic and physical maps.

Genetic Variation

• Mutations and genetic variability; types of mutations and their consequences; spontaneous and induced mutations; experiments demonstrating the random nature of spontaneous mutations; examples of physical and chemical mutagens and their mechanisms of action.

• Overview of major DNA repair mechanisms.

Mutations and Gene Function

• Analysis of nutritional mutants in Neurospora crassa and the “one gene–one enzyme” hypothesis (Beadle & Tatum).

• Effects of genetic variants on gene function and phenotype.

Chromosomal Rearrangements and Structural Variants

• Variations in chromosome number and structure: overview.

• Karyotype analysis, FISH, array-CGH.

• Aneuploidies and chromosomal disorders in humans; consequences of chromosome missegregation during meiosis.

• Structural genomic variants (deletions, duplications, translocations): mechanisms of origin and consequences.

Molecular Analysis of Genes and Genomes

• Overview of major genome analysis techniques; cloning and construction of genomic libraries; physical and genetic maps of the genome; DNA sequencing (Sanger method); genome sequencing, Human Genome Project.

Analysis of Genomic Variability and Identification of Disease Genes

• Analysis of genomic variation. Genotyping of SNPs and CNVs using microarrays.

• Linkage analysis in human pedigrees, LOD score calculation.

• Positional cloning of disease-related genes.

• Linkage analysis for diagnostic or predictive purposes.

Population Genetics

• Genetic variability in populations; allele and genotype frequencies. Hardy-Weinberg equilibrium.

• Evolutionary mechanisms that alter allele and genotype frequencies in populations (mutation, selection, genetic drift, migration, non-random mating, and inbreeding); balance among evolutionary forces.

• Introduction to the genetics of quantitative and complex traits.

• Quantitative traits, concept of heritability.

• Association mapping for the study of complex traits; linkage disequilibrium mapping and GWAS.

Readings/Bibliography

Michael L. Goldberg, Janice A. Fisher, Leroy Hood, and Leland H. Hartwell GENETICA: Dall'analisi formale alla genomica. 3 ed. Mc Graw Hill

Benjamin Pierce "GENETICA" Zanichelli

Griffiths A,J.F. et al. "Genetica. Principi di analisi formale." Zanichelli

Teaching methods

The course provides students with Integrated Digital Learning (DDL) to support learning activities and exam preparation. On the Virtuale Moodle platform, students will have access to:

• Lecture slides, along with any relevant articles and web links, made available before the lessons and organized by topic;

• Links to videos and animations as additional support to better understand the concepts explained during lectures;

• A set of problems with solutions, organized by topic.

Assessment methods

Assessment of learning is carried out through an exam designed to evaluate the achievement of the following learning objectives:

• In-depth knowledge of the topics covered during the course and listed in the syllabus

• Ability to apply this knowledge to:

  • Analyze the mechanisms of biological inheritance at the molecular, familial, and population levels

  • Understand and interpret experimental data

  • Solve basic genetics problems

 

The exam consists of a written test divided into three sections:

1. Multiple-choice questions

2. Open-ended questions

3. Problem-solving exercises

Teaching tools

• PPT presentations

• Supplementary teaching materials on Virtuale

 

Access is restricted to students enrolled in the course.

 

Students with learning disorders and\or temporary or permanent disabilities: please, contact the office responsible (https://site.unibo.it/studenti-con-disabilita-e-dsa/en/for-students ) as soon as possible so that they can propose acceptable adjustments. The request for adaptation must be submitted in advance (15 days before the exam date) to the lecturer, who will assess the appropriateness of the adjustments, taking into account the teaching objectives.

Office hours

See the website of Francesco Chemello