Describe how having the Cas9 gene at a genomic locus unlinked to the guide RNA and target site locus in an engineered gene drive system could slow the propagation of the gene drive allele in a population into which a small number of individuals carrying both the gene drive allele and the Cas9 locus are released.

In humans, congenital heart disease is a common birth defect that affects approximately 1 out of 125 live births. Using reverse transcription PCR (RT-PCR), Samir Zaidi and colleagues [(2013) Nature 498:220.223] determined that approximately 10 percent of the cases resulted from point mutations, often involving histone function. To capture products of gene expression in developing hearts, they used oligo(dT) in their reverse transcription protocol.

If one were interested in comparing the quantitative distribution of gene expression in, say, the right and left sides of a developing heart, how might one proceed using RT-PCR?

In humans, congenital heart disease is a common birth defect that affects approximately 1 out of 125 live births. Using reverse transcription PCR (RT-PCR), Samir Zaidi and colleagues [(2013) Nature 498:220.223] determined that approximately 10 percent of the cases resulted from point mutations, often involving histone function. To capture products of gene expression in developing hearts, they used oligo(dT) in their reverse transcription protocol.

Compared with oligo(dT) primers, a pool of random sequence primers requires a trickier assessment of annealing temperature. Why?

In humans, congenital heart disease is a common birth defect that affects approximately 1 out of 125 live births. Using reverse transcription PCR (RT-PCR), Samir Zaidi and colleagues [(2013) Nature 498:220.223] determined that approximately 10 percent of the cases resulted from point mutations, often involving histone function. To capture products of gene expression in developing hearts, they used oligo(dT) in their reverse transcription protocol.

How would such a high %T in a primer influence annealing temperature?

The U.S. Department of Justice has established a database that catalogs PCR amplification products from short tandem repeats of the Y chromosome (Y-STRs) in humans. The database contains polymorphisms of five U.S. ethnic groups (African-Americans, European Americans, Hispanics, Native Americans, and Asian-Americans) as well as the worldwide population.

For forensic applications, the probability of a 'match' for a crime scene DNA sample and a suspect's DNA often culminates in a guilty or innocent verdict. How is a 'match' determined, and what are the uses and limitations of such probabilities?

The U.S. Department of Justice has established a database that catalogs PCR amplification products from short tandem repeats of the Y chromosome (Y-STRs) in humans. The database contains polymorphisms of five U.S. ethnic groups (African-Americans, European Americans, Hispanics, Native Americans, and Asian-Americans) as well as the worldwide population.

What would be the value of knowing the ethnic population differences for Y-STR polymorphisms?

The U.S. Department of Justice has established a database that catalogs PCR amplification products from short tandem repeats of the Y chromosome (Y-STRs) in humans. The database contains polymorphisms of five U.S. ethnic groups (African-Americans, European Americans, Hispanics, Native Americans, and Asian-Americans) as well as the worldwide population.

Y-STRs from the nonrecombining region of the Y chromosome (NRY) have special relevance for forensic purposes. Why?

The U.S. Department of Justice has established a database that catalogs PCR amplification products from short tandem repeats of the Y chromosome (Y-STRs) in humans. The database contains polymorphisms of five U.S. ethnic groups (African-Americans, European Americans, Hispanics, Native Americans, and Asian-Americans) as well as the worldwide population.

Given that STRs are repeats of varying lengths, for example (TCTG)₉₋₁₇ or (TAT)₆₋₁₄, explain how PCR could reveal differences (polymorphisms) among individuals. How could the Department of Justice make use of those differences?