Acquired (Adaptive) Immunity
This prepares us against any subsequent infection; antibodies are made against the pathogen
What have GWAS and WES yielded for clefting?
BOTH common and rare variants have been associated with the disease.
Several GWAS have been performed to identify common variants; WES and linkage have identified rare, higher effect size genes (e.g., IRF6).
THESE VARIANTS ARE INDEED RARE, EVEN THOUGH THEY ARE ASSOCIATED WITH A COMMON DISORDER!
What mutation in humans have we been able to remove using CRISPR-Cas9?
Recently, researchers were able to correct a disease-causing mutation (in the gene MYBPC3 which when mutated causes hypertrophic cardiomyopathy that is the leading cause of sudden death in young athletes) in dozens of viable human embryos. (*the embryos were not destined for implantation)
Where was the CRISPR system used for in nature?
System evolved in bacteria to combat viruses; in this version, the bacteria do not use antibodies, but it is till an adaptive immunity using RNA system, instead.
Genome editing (also called gene editing) is a group of technologies that give scientists the ability to change an organism's DNA.
These technologies allow genetic material to be added, removed, or altered at particular locations in the genome.
What are the potential causes of clefting?
Relatively common disorder (1 in 700 births) likely due to both genetic and evironmental factors (exposure to AEDs phenytoin and valproic acid, maternal alcohol or cigerette use, herbicides).
How does the palate develop?
Medial nasal prominences and maxillary processes, fuse primary palate formeed
Secondary palatal shelves elevate (palatine processes; outgrowths of the maxillary processes) and then fuse, secondary palate formed
Non-Homologous End Joining
The CRISPR/Cas9 system cuts the desired DNA segment; the cell the reapairs the DNA by joining the ends through an indel (single nucleotide).
What would happen if our body was exposed non-terrestial substances?
If you extracted a protein from an alien or a non-earth planet, the body will produce an antibody to fight against; it will find the antibody which fits best with the pathogen.
The initial fight against a pathogen or insult in your body; immediate response, that quickly recognizes.
Homolog Directed Repair
If a donor DNA is present, the DNA is repaired by using the donor DNA as a template to add the DNA segment.
Why are we so hopeful for CRISPR-Cas9?
By far, the most promising and versatile genome editing technology to come along; this technology will eventually be brought into the clinic, and will cure some genetic disorders.
What are the genetic causes of clefting?
CNVs are one cause (7p14.1 deletion), gene mutations are another
- Growth Factor: FGF8
- Integrators of Cell Signaling for various Growth Factors: SRPY1 and 2
- Transcription Factors: IRF6, LHX8, GRHL3 and MSX1.
How have researchers used the CRISPR-Cas9 system?
Researchers have used this system to create small pieces of RNA with a short "guide" sequence that can attach (bind) to a specific target sequence of DNA in a genome.
The RNA also binds to the Cas9 enzyme. As in bacteria, the modified RNA is used to recognize the DNA sequence, and the Cas9 enzyme cuts the DNA at the targeted location.
Once the DNA is cut, researchers allow the cell's own DNA repair machinery to add or delete pieces of genetic material, or to make changes to the DNA by replacing an existing segment with a customized DNA sequence.
Where does the flue virus originate each year?
The flu virus originates every year from south east Asia because of the intimate association between humans and livestock; this is the virus from which the vaccine is prepared from.
How does the CRISPR-Cas9 system serve as acquired immunity in bacteria?
Adapted from a naturally occurring genome editing system in bacteria.
The bacteria capture snippets of DNA from invading viruses and use them to create DNA segments known as CRISPR arrays.
The CRISPR arrays allow the bacteria to "remember" the viruses (or closely related ones).
If the viruses attack again, the bacteria produce RNA segments from the CRISPR arrays to target the viruses' DNA.
The bacteria then use Cas9 or a similar enzyme to cut the DNA apart, which disables the virus.
Why are vaccines sometimes not effective against the flu?
Since the vaccine is produced from flue originating across the world, the virus that arrives in America might be slightly evolved from the vaccine version.
What does CRISPR-Cas9 sand for?
Short for clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9.
What are the two types of effects that can occur to the DNA via CRISPR-Cas9?
- Non-Homologous End Joining
- Homology DIrected Repair
How does the bacteria use the CRISPR/Cas9 system?
You can place the viral gene inside of the repeat sequence in the DNA of the bacteria
The stem loop (which is formed from repeat sequence) structure allows for the Cas-9 to bind to the structure;
Viral DNA is inside of the structure, and the enzyme cuts the DNA that matches the spacer DNA.
What potential therapeutic use does CRISPR-Cas9 have?
Researchers have begun to employ CRISPR Cas9 to correct genetic defects in model organisms such as mouse.
- In Iowa: used to remove glaucoma is mice
On what generation can CRISPR Cas9 be used?
CRISPR Cas9 can be employed in F0 animals, thus generating mutations in the very embryo undergoing the CRISPR Cas9 procedure.
This is very powerful in that no genetic crosses are necessary, saving time and effort.
How is CRISPR cas9 currently being used?
Currently, CRISPR Cas9 is used to engineer mutations in animal models in order to study gene function, or to “functionally validate” in vertebrate model organisms whether suspected human disease genes are truly causing the disease.