Scientific Disciplinary Sector (SSD)
BIO/13 - EXPERIMENTAL BIOLOGY
1° semestre dal Oct 3, 2022 al Dec 23, 2022.
Educational goals of the course: To provide a general and updated perspective of General, Cellular, Developmental and Aging Biology, with a particular emphasis on biomedical problems. To train students to evaluate critically experimental data, through the critical discussion of historical and current relevant experiments. To introduce students to instruments and techniques applied to the investigation of the cellular environment To suggest the current and other possible applications of basic biological knowledge to medical practice and therapeutics
Macromolecules common to living organisms: basic characteristics. Life’s origin: the chemical evolution hypothesis (Urey and Miller experiment).
The evolutionary theory proposed by Darwin. The modern vision of evolutionism. “Nothing in biology makes sense but in the light of evolution”. The evolution of human species. Model organisms in biology
Three major groups of living organisms: Eubacteria, Archea, Eukarya.
Main characteristics of Prokaryotes: cell structure, cell wall structure, genome, reproduction, habitats, interactions with other living organisms. Cyanobacteria: how they changed the terrestrial athmosphere.
Evolution of eukaryotes, the endosymbiontic theory. Brief recall of organelles structure and functions (from the Citology module); roles and functions of the cell memebrane. From unicellular to multicellular eukaryotes.
Cell communication, signal molecules. Cell growth and energetic metabolism in brief.
Cell cycle and its regulation. Cell division (mitosis). The nucleus; DNA, chromatin, chromosomes.
Cell death: apoptosis and necrosis.
Ploidy and reproductive strategies; sexual reproduction. Meiosis and human gametogenesis.
Nomal and pathological human karyotype. Methods of prenatal and post natal analysis . Cytogenetic anomalies and
Molecular biology: the historical experiments that led to the discovery of DNA as the genetic material (F.Miescher; Griffith, McLeod e McCarty, Hershey e Chase) . The structure of the double helix (R.Franklin, M. Wilkins, J Watson and
F Crick); DNA replication (Meselson and Stahl). RNA is an informational molecule as well (Fraenkel- Conrat)..
DNA polymerase and DNA replication “in vivo”( in prokaryotes and eukaryotes) and “in vitro” (the PCR technique).
Telomerase and telomeres replication. Denaturation, renaturation, hybridization of DNA molecules; molecular probes applications (FISH). The informational flow: from DNA to proteins. A. Garrod’s studies, the “one gene-one enzyme hypothesis by Beedle and Tatum, the central dogma of molecular biology. Roles of various RNA species in the informational flow. Gene expression in prokaryotes, polycistronic RNAs, the operons. Gene transcription in eukaryotes, promoters, RNA polymerase II, RNA processing (splicing mechanism), alternative splicing and its evolutionary significance. Messenger RNA translation, the genetic code, codons and anticodons, the “wobbling” theory. Protein synthesis in the eukaryotic cell, post-translational modifications, protein sorting and secretion. The regulation of gene expression in eukaryotes.
Chromatin structure and modifications. X chromosome inactivation in female somatic cells. DNA binding proteins which act as activators/repressors of transcription, DNA binding motives. The role of non-coding RNAs (nc-RNAs)
The beta globin genes cluster: a paradigm of space/time regulation of gene expression
Developmental biology. Master genes (e.g. the HOX selector genes) ; model organisms (Drosophila)
Master genes which act in tooth development
Cell reprogramming: from the beginning to nowadays (the experiments of Briggs, Wilmut and Dolly sheep, S. Yamanaka)
Gene expression and sex determination (SRY and DAX1 genes).
The human genome and its plasticity. Transposable elements, gene families, repeated sequences, pseudogenes. Genome evolution. Mutations: pre-adactativity (the replica-plating test by J and E Lederberg); mutations and selection, m. and fitness. Spontaneous mutations: how do they occur; induced mutations , types of mutagens , mode of action.
DNA repair systems: Proof-read repair, MMR; DSB repair, BER, NER. Ames’ test for the identification of mutagens.
Ionizing radiations, definition of LET and EBR.
Somatic mutations and cancer: target genes in tumorigenesis (proto-oncogenes, oncosuppressor genes, DNA repair genes). The process of cell ageing: causes, consequences, antidotes.
Bone biology: bone tissue composition, cell types and their roles. Molecular pathways which control the process of osteogenesis and bone remodeling.
Attendance to lessons is mandatory. Classes will consist of theorical lessons covering the whole exam program. Oral explanations will be coadiuvated by PowerPoint presentations and videos, which will be made available to students through a dedicated Department web site. In particular, the Bone Biology module will be proposed in English in a elearning modality (Power point slides + selected reviews). Additional didactic supports (multiple choice quizzes for self-assessment, journal articles , reviews, etc.) may be suggested during the course and will be made available to students for download. During the whole Academic Year, students may request personal reception to the teachers, by e mail.
Learning assessment procedures
Written examination: 25 multiple choice quizzes + 5 open questions covering all the topics discussed during classes.
This written test aims at: a) verifying students acquisition of theorical notions; b) verifying students capacity of personal rielaboration of acquired notions; c) verifying students capacity of applying what they have learnt to experimental examples. Credits will be assigned to the written test. Only in case of a positive credit (>24/30) students can optionally undergo an oral discussion. Students can withdraw the examination at any time: partial credits will be cancelled in this case.