1. The document compares genetic and linguistic diversity in Europe and finds some correlations between the two.
2. Structural features of languages may provide a better basis for comparison than vocabulary. Principal component analysis of genetic and linguistic data show some similarities in clustering.
3. Recent population mixing can account for some inconsistencies between the genetic and linguistic patterns. Overall, geography, genetics, and language are interrelated but influenced by separate evolutionary processes over long time periods.
Johann Friedrich Miescher first characterized DNA in 1869 after extracting it from cell nuclei where he called the substance "nuclein". Through the late 19th century, scientists determined DNA's components include sugars, phosphates, and nitrogenous organic bases. In the early 20th century, models proposed DNA as made of repeating tetranucleotide units. Rosalind Franklin's X-ray diffraction images and the work of Chargaff supported that DNA had a regular structure. Watson and Crick then used this evidence to propose their famous double helix model of DNA structure in 1953, with two intertwined strands held together by base pairing. This established DNA as the genetic material and explained its ability to self-replicate and
1. The document discusses three main questions regarding human evolutionary genetics: the debate between hybridization models vs. the Southern dispersal route out of Africa, the coevolution of cultural and biological diversity, and challenges to the persistence of racial paradigms given genomic data.
2. Regarding the first question, the author notes several problems with hybridization hypotheses and presents evidence supporting an earlier dispersal of modern humans out of Africa via a Southern route, avoiding contact with Neanderthals.
3. For the second question, the author reviews evidence that increases in brain size did not necessarily correlate with genes associated with cognitive functions, and that cultural and linguistic changes likely evolved in parallel with biological changes.
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The document discusses the history and structure of DNA. It describes how DNA was discovered to be the genetic material through experiments in the 1800s and 1900s. Key figures like Watson, Crick, Franklin and Chargaff contributed to determining DNA's double helix structure and the rules of base pairing between A-T and G-C. The structure forms a spiral with the bases on the inside and a sugar-phosphate backbone on the outside, held together by hydrogen bonds between the paired bases.
Una lezione dettagliata sulla struttura, funzione e meccanismo di replicazione della più importante molecola biologica
(La presentazione contiene immagini reperite sul web, utilizzate per fini puramente didattici; qualora fossero stati infranti copyright, si prega di segnalarlo all'autore, grazie)
Cell differentiation and differential gene expressionStephanie Beck
Cells from the same individual can have different appearances despite having identical DNA because cells can selectively express different genes. Early in development, stem cells differentiate into specialized cell types by activating different sets of genes through gene regulation. Gene expression involves using DNA as a template to produce mRNA and then translate it into specific proteins. Different cell types produce different proteins by expressing only the genes required for their function.
This document provides an overview of topics to be covered in the second semester including genetics, evolution, and classification of life. Genetics will cover DNA structure and function, including DNA replication, gene expression, mutations, inheritance of traits, and biotechnology. Evolution will discuss gene pools, variation, natural selection, evidence for evolution, adaptations, and human impacts on gene pools. Classification of life will focus on the kingdoms Animalia and Plantae, comparing nervous and vascular systems, and plant reproduction. Videos and online resources are provided for further learning on genetics and genetic modification.
This document discusses various patterns of inheritance including complete dominance, incomplete dominance, codominance, X-linked traits, Y-linked traits or holandric inheritance, multiple alleles, epistasis, pleiotropy, polygenic inheritance, and multifactorial inheritance. Examples are provided for each type of inheritance pattern using traits such as hair color, coat color, spotting patterns, and infertility. The document is intended to review key concepts regarding inheritance patterns.
Genetically Engineered Food: Is There Any Other Kind?Dan Graur
- All food is genetically modified through various natural and artificial processes. Opponents of genetically modified food are scientifically misinformed and causing harm.
- Domestication of plants and animals through artificial selection amounts to genetic engineering and has been practiced for thousands of years to create foods like corn, wheat, bananas, and dairy cows.
- Modern genetic engineering techniques allow more precise modifications but achieve the same effects as long-established selective breeding practices. Golden rice aims to help prevent blindness in children through vitamin A supplementation.
- There is no scientific evidence that genetically modified foods are inherently unsafe to consume. Nostalgia for pre-agricultural foods ignores how much genetic changes have enhanced the food supply.
X. laevis è un importante organismo modello in biologia evolutiva dello sviluppo, tossicologia, etologia, neurobiologia, endocrinologia e biologia dei tumori; grazie alle recenti tecniche di Genome editing, ha acquisito una posizione rilevante anche nel campo della Genetica.
Corso di Aggiornamento di Ginecologia dell’Infanzia e dell’Adolescenza: Il pediatra e il ginecologo dall’infanzia all’adolescenza per la salute di domani.
25-27 Gennaio 2018, Messina.
I progressi tecnologici raggiunti nel campo delle strategie di sequenziamento degli acidi nucleici ("Next Generation Sequencing", NGS) permettono oramai di ottenere con facilità le informazioni contenute all’interno dell’intero genoma umano. Ma solo una piccola percentuale (stimata a 1,6%) del genoma umano viene tradotto nelle proteine che fanno funzionare il corpo umano. Il sequenziamento esomico ("Whole exome sequencing") si concentra proprio sulle parti del genoma che codificano le proteine ("i geni") perché la ricerca di varianti in tali regioni permette di trovare le modificazioni funzionali delle proteine che sono associate a malattie. Dovendo sequenziare solo circa 1/60 dell’intero genoma si ha la possibilità di avere una migliore accuratezza e di ridurre tempi e costi del sequenziamento. Per questo motivo il sequenziamento esomico è diventato uno dei metodi di diagnosi genetica più utilizzato dai medici (sopratutto nel caso in cui non ci siano ipotesi sui geni coinvolti nella malattia).
Meccanismi epigenetici e transgenerazionali nei disturbiClaudio Lombardo
Recenti scoperte suggeriscono che le modifiche epigenetiche possono mediare i cambiamenti del fenotipo e delle funzioni del cervello, manifestandosi anche di generazione in generazione. Poiché la risposta dell'organismo alle esposizioni ambientali comporta un’alterazione dell’espressione genica, identificare i “cambiamenti epigenetici regolatori” che sono coinvolti potrebbe rappresentare la chiave per prevenire ed intervenire potenzialmente su determinati fenotipi.
Perché alle Olimpiadi le gare di sprint le vincono sempre atleti caraibici, le maratone gli africani dell'est, che però nel nuoto non combinano niente? Non sarà che ci sono differenze razziali? La risposta, ancora una volta, è no.
1. Cap. 17 Regolazione dell’espressione genica negli Eucarioti. Pp. 493-502, 508-510
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4. Regolazione negli Eucarioti Fattori trascrizionali Operano in trans: sono molecole diffusibili Attivatori, repressori Sequenze regolatrici Attive solo in cis: sono siti del DNA Promotori (vicini), enhancer, silencer (lontani) GGGCGG CCAAT TATA -110 -40 -30 1 “GC” box “CCAAT” box “TATA” box Schema di promotore
13. Looking for speech genes Bishop (2002) In the portions of the genome that differ between chimpanzee and human, can we find a gene or genes that are crucial for language? Speech genes?
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15. Several language isolates are also genetic isolates: the Basques Calafell & Bertranpetit (1993) Language-genetics correlations
16. Famiglia KE con una grave forma di dislessia (incapacità di sviluppare un discorso articolato) Mutazione nel gene FOXP2
21. Looking for speech genes: gene expression comparisons Enard et al. (2002)
22. We have largely the same genes as chimpanzees, and these genes do the same things in much of our bodies, but not in the brain Enard et al. (2002) Species-specific gene expression patterns: Large changes in gene expression in the human brain.
23. We have largely the same genes as chimpanzees, and these genes do the same things in much of our bodies, but not in the testis Khaitovich et al. (2005) Species-specific gene expression patterns: Small changes in gene expression in the human brain.
24. Increased levels of expression of CA2 in the human brain, of TWIST in the chimp and macaque brain Caceres et al. (2003) 90% of 169 shared genes upregulated in the human brain
25. Geni inattivi sono metilati Contengono residui di 5-metil-citosina Il contenuto di 5-metil-citosina è inversamente correlato al livello di espressione genica Sostituendo alla citosina un suo analogo non metilabile, la 5-azacitidina, si attivano geni normalmente inattivi
26. Regioni cromosomiche attive hanno struttura meno condensata che le rende sensibili all’azione della DNA-asi Eritroblasti: Taglio delle regioni per la beta-globina e l’ovoalbumina
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