tommaso.russo@unina.it

Chiediamoci sempre come accade … Ignác Fülöp Semmelweis 1818-1865

Homo sapiens (una singola specie): 7.000.000.000 di individui Insetti (1.000.000 di specie) Termiti (2800 specie) Un termitaio: fino ad alcuni milioni di individui

Lontani Vicini Diversi Simili

Procarioti ed Eucarioti

-> nucleo <- citoplasma

Struttura e Manutenzione del Genoma Il genoma Cromatina e Cromosomi Replicazione del DNA Riparo dei danni al DNA Ricombinazione Attività del Genoma Sintesi e maturazione dei trascritti Sintesi delle proteine Regolazione dell’espressione dei geni

Genomi dei Procarioti Una molecola circolare E. coli 4,6 x 106 coppie di basi Intero genoma quasi tutto codificante Trascritto in mRNA policistronici

GENOMI

COMPLESSITA’ DEL GENOMA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA… TTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTT… ACGACGACGACGACGACGACGACGACGACGACGACGACGACGACGACG… TGCTGCTGCTGCTGCTGCTGCTGCTGCTGCTGCTGCTGCTGCTGCTGC… AGCCAATGGACATGGATCACATGGATGGATGATGATGGATGCCCAATG… TCGGTTACCTGTACCTAGTGTACCTACCTACTACTACCTACGGGTTAC…

Genoma umano 46 cromosomi lineari 22 autosomi presenti in duplice copia (genoma diploide) 2 cromosomi sessuali X Y maschio; X X femmina 3,6 x 109 coppie di basi (lunghezza del genoma aploide) CARIOTIPO UMANO NORMALE

UN CARIOTIPO UMANO PATOLOGICO Leucemia mieloide cronica

Glucosio-6-fosfato deidrogenasi

Deficienza di Glucosio-6-fosfato deidrogenasi (favismo) Cambiamento di un singolo nucleotide: mutazione

Il genoma di chi? I siti polimorfici sono uno strumento essenziale per la medicina

all human beings are actually 99.9% the same … but not identical Despite the many differences between our DNA, overall, all human beings are actually 99.9% the same This is just one of the multitude of genetic information that was taken from the Human Genome Project One of the challenges facing us now is determining how all this genetic information will be used. How will we work together to prevent it from being used to stigmatize and discriminate? How will we use this information to improve the quality of life for human beings? We don’t have a choice about whether or not to participate in the Genetic Age. We are in it.

Phenotypic Variation Single Nucleotide Polymorphism (SNP) Polymorphism Gene Expression Phenotype - outside appearance or result of the genes in a person Polymorphism – differences between any two people’s DNA Phenotypic variation is due to many factors within the genome We can learn about this variation by looking at SNPs and other polymorphisms, and the gene expression of different people This can help us learn about the genetic basis for variation in human health Discovery of the genetic basis for the variation in health and appearance among human beings

OUTBREEDING

All Disease is a Result of Genes Interacting with the Environment… Infectious Disease Drugs Lifestyle Choices Exercise Diet Exposures Genetics Environment Tay-Sachs HIV / AIDS Diabetes Cystic Fibrosis Heart Disease Lead Toxicity Cancer Most diseases are a result of the interaction of disease with environmental factors such as exercise, obesity, drugs, infectious diseases, lifestyle choices, and exposure. The amount that genetics and the environment play in the disease is variable: Tay-Sachs and Cystic Fibrosis are almost 100% genetic, with little environmental influence Diabetes and Cancer have both a heavy genetic component as well as are affected by environmental factors Heart Disease and HIV/AIDs lean more towards the environment Lead Toxicity is purely due to environmental factors

Che cosa è un SNP (single nucleotide polymorphism) …..ACTGTGAGGATCAGGATCAGGTGACGGATGGACTGA….. …..ACTGTGAGGATCAGAATCAGGTGACGGATGGACTGA….. 70% AG 10% AA 20% GG

STRUTTURA DELLA CROMATINA

NUCLEOSOMI

NUCLEOSOMI

ISTONI

Figure 4-33a Molecular Biology of the Cell (© Garland Science 2008)

ASSEMBLAGGIO DEL NUCLEOSOMA Figure 4-26 Molecular Biology of the Cell (© Garland Science 2008)

Figure 4-33b Molecular Biology of the Cell (© Garland Science 2008)

Figure 4-34 Molecular Biology of the Cell (© Garland Science 2008)

Genetica ed Epigenetica Figure 4-35 Molecular Biology of the Cell (© Garland Science 2008)

MODIFICHE DEGLI ISTONI Figure 4-38 Molecular Biology of the Cell (© Garland Science 2008)

Codice istonico Figure 4-44a Molecular Biology of the Cell (© Garland Science 2008)

Codice istonico Figure 4-39b Molecular Biology of the Cell (© Garland Science 2008)

EU- ed ETERO-CROMATINA

Compattamento di Nucleosomi

LIVELLI DI COMPATTAMENTO DELLA CROMATINA

TOPOLOGIA DEL DNA E COMPATTAMENTO DELLA CROMATINA Procarioti Eucarioti

Denaturazione e Superavvolgimenti L = T + W

RISOLUZIONE/INTRODUZIONE DI SUPERAVVOLGIMENTI Topoisomerasi I

TOPOISOMERASI I: Meccanismo

Topoisomerasi II

Topoisomerasi II: Meccanismo

Inibitori di Topoisomerasi I: Topotecan (der. Camptotecina) Staker et al. (2002) PNAS 99,15387

Inibitori (veleni) di Topoisomerasi II: Etoposide Topo II poisons that include many clinically useful anticancer drugs, such as doxorubicin, daunorubicin, mitoxantrone and m-AMSA in addition to etoposide, stabilize the cleavable complex. Altri inibitori di Topoisomerasi II: doxorubicina, daunorubicina, mitoxantrone

Riepilogo Genoma Polimorfismi Cromatina Cromosomi Topologia Topoisomerasi