2 DNA fragment Nitrogenous bases: A, T, G e C. In a eukaryotic cell, the DNA is localized inside of the nucleus, compacted and organized in a structure called cromosome.
3 Chromosome and Genotype In diploid species, like humans, having 2n pairs of chromosome, where n is the number of differentes chromosomes.The genotype is the set of all chromosomes. (in humans are 46).
4 Haplotype In haplotypes species, have n chromosomes, only one copy. In humans the genotype is the set of 23 chromosomes from the father and another 23 from the mother.
5 EvolutionThese chromosomes are passed with very great fidelity from one generation to the next. However, occasionally a mutation has occurred and effectively changed one base to another.The variation occurred in genetics sequences are many types, but the main are mutations and polymorphisms.
6 PolymorphismWhen several chromosomes from a population are compared, a site where a mutation occurred in the past may be found, and some chromosomes will have the original base and others will have the new base, i.e. the population will be polymorphic.The variation of DNA sequences inside of the same species and have at least two types, is called alleles.Traça (Biston betularia) brancaVariante preta da traça
7 PolymorphismA special kind of polymorphism is the target of many researchs, because of the major variation frequence in DNA humans.This kind of ploymorphism is called: Single Nucleotideo Polymorphism ou SNP.
8 Make up about 90% of all human genetic variation. What are SNPs ? (Single Nucleotide Polymorphisms)Common DNA sequence variations among individuals in genome wherein the least frequent allele has an abundance of 1% or greater.Make up about 90% of all human genetic variation.Some SNPs are reported to be highly related to diseases or influence cells response to a drug.
9 A SNP might change the DNA sequence What are SNPs?SNPs are DNA sequence variations that occur when a single nucleotide (A,T,C,or G) in the genome sequence is altered.Example:A SNP might change the DNA sequenceAAGGCTAA to ATGGCTAA.For a variation to be considered a SNP it must occur in at least 1% of the population.SNPs make up about 90% of all human genetic variation.
20 What are SNPs? SNPs occur every 100 to 300 bases along the 3-billion-base human genome.Two of every three SNPs involve the replacementof cytosine (C) with thymine (T).SNPs can occur in both coding (gene) andnoncoding regions of the genome.Many SNPs have no effect on cell function, butscientists believe others could predispose peopleto disease or influence their response to a drug.
21 SNPs have various functions G/TpromoterG/TG/CGUAGTFBS5’UTRatggacgtactggtgtctgagtgctccgcg3’UTRA/GG/TType 1 transcriptTranscrip. FactorBinding SitesType 2 transcriptType 3 transcriptAltering the encoded proteinAlternative splicingPremature terminationTranscription regulationType 1 proteinM D V L V S E C S AM D V L V S E S S AType 2 proteinType 3 protein
22 Important SNP Resource a web resource of single nucleotidepolymorphisms (SNPs) within protein domainstructures and sequencesAreum Han, Hyo Jin Kang, Yoobok Cho,Sunghoon Lee, Young Joo Kim and Sungsam GongNAR (Web Server issue):W642-W644doi:Site:
23 dbSNP: the NCBI database of genetic variation Sherry ST, Ward MH, Kholodov M, Baker J, Phan L, Smigielski EM, Sirotkin K. Nucleic Acids Research (NAR) 2001; 29:
24 Recent SNPs Sites and BDs Uzun, C. M. Leslin, A. Abyzov, and V. Ilyin Structure SNP (StSNP): a web server for mapping and modeling nsSNPs on protein structures with linkage to metabolic pathways NAR, July 13, 2007; 35(suppl_2): W384 - W392.J. Park, S. Hwang, Y. S. Lee, S.-C. Kim, and D. Lee a database of ethnically variant single-nucleotide polymorphisms NAR, January 12, 2007; 35(suppl_1): D711 - D715.
26 Árvores Filogenéticas Árvores filogenéticas são árvores que representamas relações evolucionárias entre as diferentesespécies.Cada nó com descendentes é considerado oancestral comum mais recente destes descendentes.Muitas vezes o comprimento das arestas representaa distância em tempo de evolução.Há várias formas de representação.
28 Árvore FilogenéticaPhylogenetic tree showing the relationship between the archaea and other forms of life.Eukaryotes are colored red, archaea green and bacteria blue. Adapted from Ciccarelli et al. 2006
29 Árvores Filogenéticas São construídas- Com base em distâncias (diferenças) entreseqüências de DNA das espécies envolvidas.- Sob a hipótese de que todas evoluíram deum ancestral comum.Muitas vezes são representadas através dedendogramas.
30 Phylogeny Orangutan Gorilla Chimpanzee Human From the Tree of the Life Website, University of ArizonaOrangutanGorillaChimpanzeeHuman
31 A Árvore da Vida da SCIENCE A revista Science tem uma Árvore da Vida on-line:http://www.sciencemag.org/feature/data/tol/
32 Evolução Convergente e Divergente Evolução é dita convergente quando organismosque não são fortemente relacionados desenvolvemcaracterísticas similares de forma independente.Ex: Asas de insetos, aves e morcego.Evolução é dita divergente quando organismosque são fortemente relacionados desenvolvemcaracterísticas diferentes.
34 Filogenia PerfeitaUm conjunto de seqüências S tem uma filogenia perfeita se existe uma árvore filogenética sobre S tal que:- Cada estado de cada caracter ocupauma sub-árvore, ou- Nenhum caracter tem back-mutationou evolução paralela.
35 Exemplo A=(0,0), B=(0,1), C=(1,0), D=(1,1) não tem uma filogenia perfeita.Intuitivamente,- O 1o. elemento associa (A, B) e (C,D)- O 2o. elemento associa (A, C) e (B, D)