Name: snps as genetic markers and variants
Uploaded: 2021-04-07T12:12:00.000Z
Duration: 1 min 5 s
Channel: JoVE
Description: Single nucleotide polymorphisms, or SNPs, are small DNA changes at one specific genomic position. They are the most common type of sequence variation in the human genome. A point mutation counts as an SNP when it appears in more than 1% of the population.

K12 Standards

Arizona Science Standards

High School

Life Science

HS.L3

HS.L3U3.26

Single Nucleotide Polymorphisms-SNPs

Quando si confrontano più genomi umani, si osservano variazioni nelle sequenze.
Le variazioni dovute alla sostituzione di un nucleotide sono chiamate polimorfismi a singolo nucleotide o SNP.
Le variazioni dovute all'inserimento o alla delezione di una sequenza di nucleotidi di lunghezza inferiore a un kilobase sono chiamate indel.
Se un'inserzione o una delezione di nucleotidi viene copiata un numero variabile di volte nello stesso genoma, si parla di variazione del numero di copie o CNV. Spesso, le CNV coinvolgono grandi tratti di DNA di lunghezza superiore a un chilometro.
Un aplotipo è un insieme di geni ereditati da un singolo genitore. Un genoma può essere diviso in blocchi di aplotipi che contengono gruppi di polimorfismi.
Poiché si verificano pochi incroci tra cromosomi omologhi durante ogni meiosi, i blocchi di aplotipi sono stati ereditati in un gruppo collegato attraverso le generazioni.

<ol>
	<li>Chanock, Stephen. "Geni candidati e polimorfismi a singolo nucleotide (SNP) nello studio della malattia umana." Marcatori di malattia 17, n. 2 (2001): 89-98. <a href="https://downloads.hindawi.com/journals/dm/2001/858760.pdf">https://downloads.hindawi.com/journals/dm/2001/858760.pdf</a></li>
	<li>Gao, Rongsui, Wenhong Zu, Yang Liu, Junhua Li, Zeyao Li, Yanling Wen, Haiyan Wang et al. "Quasispecie di SARS-CoV-2 rivelate dall'analisi dei polimorfismi a singolo nucleotide (SNP)". Virulenza 12, n. 1 (2021): 1209-1226. <a href="https://www.tandfonline.com/doi/full/10.1080/21505594.2021.1911477">https://www.tandfonline.com/doi/full/10.1080/21505594.2021.1911477</a></li>
</ol>

polimorfismi a singolo nucleotide - snp

Un polimorfismo a singolo nucleotide o SNP è una variazione di singolo nucleotide in una specifica posizione genomica in una vasta popolazione. È il tipo più diffuso di variazione di sequenza riscontrata nel genoma umano. Le mutazioni puntiformi che si verificano in più dell'1% della popolazione si qualificano come SNP. Questi sono presenti in media una volta ogni 1000 nucleotidi nel genoma umano. La sostituzione di una purina con un'altra purina (A/G) o di una pirimidina con un'altra pirimidina (C/T) è nota come transizione. Al contrario, la sostituzione di una purina con una pirimidina (A o G / C o T) o viceversa è detta trasversione. Negli SNP, le transizioni sono più importanti delle trasversioni.

Per studiare le variazioni genetiche presenti nel genoma vengono utilizzati diversi metodi, noti anche come genotipizzazione. A differenza degli SNP, le ripetizioni in tandem singolo (STR) coinvolgono ripetizioni di-, tri- o tetranucleotidi. Gli scienziati spesso utilizzano la genotipizzazione degli SNP rispetto agli STR, poiché gli SNP sono più abbondanti e stabili e alcuni SNP influenzano direttamente il fenotipo.

Nella maggior parte dei casi, gli SNP si trovano negli introni, che non codificano alcuna proteina. Tali SNP possono essere utilizzati come marcatori biologici per individuare i geni associati a una particolare malattia. Se l'SNP è presente all'interno di un gene o in una sequenza regolatrice vicino al gene, può influenzare la funzione e causare malattie.

Polimorfismi a singolo nucleotide - SNP

Un polimorfismo a singolo nucleotide o SNP è una variazione a singolo nucleotide in una specifica posizione genomica in una vasta popolazione. È il più diffuso ...

Education

Didattica

JoVE Core

Molecular Biology

Biologia Molecolare

Unit 2

Unità 2

Analyzing Gene Expression and Function

Analisi dell'espressione e della funzione genica

KEY TERMS AND CONCEPTS

TERMINI E CONCETTI CHIAVE

snps as genetic markers and variants

Single nucleotide polymorphisms, or SNPs, are small DNA changes at one specific genomic position. They are the most common type of sequence variation in the human genome. A point mutation counts as an SNP when it appears in more than 1% of the population.

SNPs as Genetic Markers and Variants

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Single nucleotide polymorphisms, or SNPs, are small DNA changes at one specific genomic position. They are the most common type of sequence variation in the human genome. A point mutation counts as an SNP when it appears in more than 1% of the population.

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key terms and concepts

Explore SNPs as common DNA variants, including transitions, transversions, and how they help scientists find genes linked to disease.

SNPs as Genetic Markers and Variants | JoVE K12

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SNPs as Genetic Markers and Variants

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