D 1.3 Mutations and gene editing +HL

huntingtons disease cause and symtoms

a mutation of the HTT gene which mutates CAG., which cause neuronal failure

gene knockout

a technique to investigating a function of a gene by removing the gene

what are we looking for after gene knockout?

the phenotype of the offspring

problems of using mice and of gene knockout in general

15% no offspring because gene that was removed was important

phenotype changes might not be visible

changes in mice do not equal to change in humans

how is gene knockout technology used/made?

• replacement of a gene with a suitable sequence to delete gene X in a mouse

• insertion of knock out diploid cells which contain one knocked out gene and one normal gene

• implantation of blastocyst into surrogate mother mouse

• study the offspring to see if there is a visible change in the phenotype

what can gene knockout be used for?

to identify genes that have predisposition to cancer

CRISPR meaning

clustered regularly interspersed short palindromic repeats

Describe the use of gene knockout technology in research.

a. gene knockout technology is a genetic engineering technique/intentional alteration in the sequence of a gene;

b. making a gene inactive;

c. using site specific nucleases / CRISPR;

d. researcher observes changes in phenotype of organism;

e. allows researcher to determine function of the gene;

f. entire library of knockout organisms exists;

g. made available to researchers;

steps of CAS9 activity

• Cas9 moves along the target DNA molecules

• it recognizes a gene that is viral and is not bacterial

• it removes the gene with endonucleases, disabling the viral activity

example of using Crispr sequence in sickness?

sickle cell anemia: mutation on chromosome 11, and CRISPR can be used to modify bone marrow cell since this mutation is only of one base

define highly conserved sequences