25 Questions
What is the relationship between the 13910 position genotype and methylation levels at the promoter region?
Individuals with the T variant have lower methylation levels at the promoter region.
What happens to lactase expression levels after weaning?
Lactase expression decreases due to methylation at the enhancer site.
Which factor appears to be continuously associated with lactase phenotypes in the text?
Methylation levels at the enhancer site
How does the genotype at the 13910 position affect methylation levels at the enhancer site?
Affects methylation negatively
What role does dietary change or lactose intake play in increasing lactase production?
Has no effect on lactase production
What may be a potential reason for differences in symptoms among lactase non-persistent individuals?
Gut flora composition
How do multiple independent mutations relate to various populations?
They are maintained in populations related to lifestock herding culture.
Which factor outperforms the previously known genotype in predicting lactase persistence vs. lactase non-persistence phenotype?
-13910 position genotype combined with enhancer methylation
How does having the T variant in the -13910 position affect CpG site methylation at the enhancer?
-13910 T variant decreases methylation levels.
What is the role of the enhancer region in the context of lactase persistence?
It interacts with regulatory proteins to influence LCT gene expression.
How do SNP variants contribute to lactase persistence?
They confer lactase persistence by mutating specific nucleotide positions.
Why is it significant that individuals with a lactase persistence SNP at one position have a non-persistent SNP at others?
It suggests that these mutations are independent and region specific.
How do mutations contribute to the evolution of new traits like lactase persistence?
Mutations gradually change gene regulation to evolve new traits.
What is the significance of having the variant T at the -13910 position in the enhancer region?
It increases expression of the luciferase gene
How do SNPs at the enhancer region influence LCT enzyme activity?
They increase LCT enzyme activity by enhancing gene expression
What does the study suggest about individuals with different genotypes at the -13910 site?
Their lactase activity differs based on their cc, ct, or tt genotypes
How does having different genotypes at the -13910 site influence DNA methylation levels?
Methylation levels vary depending on the CC, CT, or TT genotypes
How does the presence of SNP variant T enhance gene expression at the MCM6 region?
By facilitating better interaction between activators and enhancers
What is the impact of having a C instead of a T at the position that allows activator binding?
Decreases luciferase gene expression
What is the genetic basis for lactase persistence mentioned in the text?
Methylation at the enhancer region
Why did lactase persistence become a common trait in some populations?
Selective advantage due to dairy consumption
What happens to potentially lactase persistent gene variants if there is no selective advantage for them?
They get eliminated through genetic drift
How are gene variations typically originated according to the text?
Through mutation
Which process leads to the elimination of mutations that do not offer a selective advantage in a population?
Genetic drift
What is the significance of maintaining affinity between activator and enhancer for the LCT gene?
Promotes lactase persistence
Test your knowledge on the experiment by the Tishkoff team involving vectors with SNP variants C and T, showing a 20X difference in light production. Understand the impact of the SNP variant on Luciferase gene expression in human intestinal cells.
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