Courtney Peters Chapter 6: Finding mutant phenotypes for cloned genes
1. “Reverse genetics” refers to the process of finding a mutant phenotype for a gene whose DNA sequence is known.
a. What are some of the situations in which the DNA sequence of a gene, and perhaps evidence about its function, can be known before the mutant phenotype is known?
Gene expression can be used to find out the function of a gene before its mutant phenotype as well as genetic screening.
b. Since genome sequences are available for all model organisms and many other species, is the distinction between “reverse genetics” and “forward genetics” still meaningful? If so, how is this useful?
I do believe it is still meaningful as there is a distinction between both reverse and forward genetics. As not
…show more content…
What are these two core components and what are their functions? Since the specific molecules used to perform the functions may vary or better versions may be developed, recognizing their functions is essential to understanding the basis for CRISPR.
The first core components of the CRISPR-Cas9 system are an endonuclease Cas9 containing two catalytic nuclease domains and a single guide RNA (sgRNA). CRISPR/Cas9 can be used to generate knock-out cells or animals by co-expressing a gRNA specific to the gene to be targeted and the endonuclease Cas9. The genomic target can be any 20 nucleotide DNA sequence, provided it meets two conditions, sequence is unique compared to the rest of the genome and the target is current directly upstream of a Protospacer Adjacent Motif (PAM). Second CRISPR locus which is involved in genetic memory. b. What are some of the similarities and differences between CRISPR and the Crelox technique described in the chapter? Similarities- both are tools for directing modification to a specific DNA sequence within the organism
Differences- CRISPR identifies and alters any selected site in the present genome. While, Cre-LoxP must be inserted into the