An article written for Science news by Anna Gibbs discusses the use of genetic engineering in place of cloning to bring back extinct species. Geneticists hope to accomplish this feat by utilizing gene-editing technology such as CRISPER. The largest drawback to this method is that the species being "resurrected" will only be a close replicant to the extinct species, and not genetically identical. The new species would only resemble its extinct counterpart as closely as scientifically possible. The exact genome would be necessary to create a perfect replicant of the extinct species, but that may be an impossible task as geneticists can only sequence what they can find from what is still preserved from possibly ancient samples if the species went extinct long ago. 

    Opinion: The article mentions bringing back the woolly mammoth. The implications of bringing back such a large animal into the ecosystem may be detrimental. It may be more practical if this technique were used only to stop the extinction of existing endangered species.

Improving Animal Welfare Through Gene-Editing

 

    Researchers at Kent State University have newly found a way to gene edit and create fully female and fully male litters of mice with 100% efficiency. This could be incredibly useful in dairy and egg production. Seeing as the females in both of these industries are the required sex and the males get disposed of. In chickens, the roosters are culled and in dairy, the bulls are sent to auction or slaughtered. If we could create a herd of 100% females there would be no need to slaughter any males. This is not only profitable for the farmers but improves the welfare of these animals. Researchers also brought up the idea behind the use of these litters for science. Generally, in research, only one sex will be studied they explain and the others are removed and disposed of. In this case, they can genetically create research litters of the sex they prefer, therefore not "wasting" any animal. Decreasing the slaughter rate of many animals that were not specifically bred for that reason. This is a huge step in the way of animal welfare and quality of life. A note to make is that there were also no harmful effects to the surviving gene-edited offspring. The researchers make clear although this is a big step in genetic research, any future use in agriculture would have to be studied extensively before use on any farm.

https://www.sciencedaily.com/releases/2021/12/211203081525.htm

https://www.science.org/content/article/gene-editing-produces-all-male-or-all-female-litters-mice

Scientists Try CRISPR To Fight HIV

A study was performed by Chinese researchers in the New England Journal of Medicine where they used CRISPR to try to cure a patient's HIV.  They did this by using blood cells that were altered to resist AIDS.  This was also the first published study where scientists used CRISPR to treat a disease where the DNA that was changed was restricted to that person only.  They tested this on a 27-year-old man who had HIV.  He needed a blood stem cell transplant in order to treat cancer.  In two prior cases, two men were cured of both diseases by transplants from donors who had a gene mutation that actually prevented HIV from ever entering the cells.

Because donors with this resistance to HIV are rare, these Chinese researchers tried to "edit" the genes in order to imitate this mutation.  Although this transplant didn't cure the mans HIV, it did put him in remission and the genes that were "edited" were still working even 19 months later.  Of course, scientists need to continue to work on this to make gene editing more efficient, but one of the upsides to this gene-editing technique was that in multiple different tests, it was shown that gene-editing didn't have any unwanted effects on any other genes.

This study shows how big of an advancement CRISPR could be in curing and preventing diseases if they continue to test it.  What I found the most important in this research was that even though the purpose of curing the HIV virus in this particular study didn't work, it showed that it didn't have any unwanted effects on other genes that weren't being edited.  If that were the case, it could have led to many more issues with different genes being edited that were never meant to be.

https://japantoday.com/category/features/health/a-gene-editing-first-scientists-tried-crispr-to-fight-hiv
http://sites.tufts.edu/crispr/applications/hiv-treatment/
https://www.cbsnews.com/news/gene-editing-crispr-remove-hiv-infection-in-mice/

Scientists Breed Pigs with Life-Saving Gene Alteration

Piglets are the main focus for PRRS prevention.

Great leaps have been made in research of the pig farming industry as scientists at University of Edinburgh have managed to use gene-editing techniques to halt the infection of one of pig-farmers' worst enemies: Porcine Reproductive and Respiratory Syndrome. Porcine Reproductive and Respiratory Syndrome (PRRS) is a costly and deadly disease that plagues the domesticated pig population with high death rates for both pregnant sows, their fetuses, and young piglets. The virus can cause abortion and mummification of fetuses, as well as severe respiratory issues and extreme weight loss, which causes a large percentage of the piglet population to die before reaching adulthood. This article summarizes the discoveries and the mechanisms behind them.


The pathway for the PRRS virus has now been linked to a scavenger receptor on macrophages known as CD163, a receptor also responsible for managing inflammation and removing hemoglobin. Scientists have managed to pinpoint CD163 as the infection site for PRRS, but due to the other important contributions of CD163, they could not delete the receptor as a whole. However, in the originally published journal detailing the research, the structure of CD163 is described as "pearls-on-a-string", with nine scavenger receptor crysteine-rich domains (SRCR), and from this, the team of Edinburgh managed to pinpoint SRCR5, the domain responsible for the infection of pigs with PRRS.

Using gene-editing technologies, researchers injected 24-39 zygotes with the SRCR5 deleted genes and ended up with 32 live piglets. From this, they took the two pigs that showed the desired deletion of the exon 7 (which is linked to SRCR5), crossed them, and resulted in a mixture of different genotypes, all of which had deletion of exon 7 in varying forms. Exposing these individuals to the PRRS virus did not result in infection, while still maintaining normal functions within the CD163 scavenger receptor. From this experiment, not only did the team at Edinburgh prove that the deletion of SRCR5 can prevent infection of one of the deadliest viruses in domestic pigs, but also that it can be safely and successfully passed on to other generations.

Genome editing: Pressing the 'delete' button on DNA

The Johnson lab recently created the Crispr-Cas9  a new technique for editing genomes. It can be used to delete any piece of "non-coding DNA" The lead researcher Carlos Pullido created a software  called CRISPETa, the user tells CRISPETa which region they want to delete and the software returns sgRNAs that can be used by the researchers. It is expected that CRISPR will lead to being able to reverse disease causing mutations.  Although right now CRISPR is in its experimental stages i believe this new technology could revolutionize not only  the way we approach gene therapy in humans but also lead too domestication of wild crops. Rather than mix the DNA of different species this new gene editing software can speed up the time it takes to domesticate wild foods by editing existing genetic material. 

https://www.sciencedaily.com/releases/2017/03/170302144002.html

http://www.seeker.com/cripsr-gene-editing-domesticate-wild-crops-frankenfoods-2305925383.html

Breakthrough in Gene Therapy for Sickle Cell Disease

Breakthrough in Gene Therapy for Sickle Cell Disease

 
                                              

A team of researchers are making breakthroughs when it comes to correcting defective sickle cells with a gene-editing tool called CRISPR. This tool can fix genes that cause sickle cell, and thus can lead to promising gene therapies for this ailment.

The researchers have been able to prove that they can use such mended cells to make a “high functioning hemoglobin molecule” and have it transfer oxygen to cells. When the stem cells were placed in mice they found it successful in treating disorders such as sickle disease and thalassemia.

CRISPR is both an enzyme and “guide RNA” that can cut the part of the gene that causes mutation out and use other tools to make the correct sequence.

Sickle Cell is a disease that make normal cells turn into a sickle shape, which significantly decrease the amount the oxygen being transported around the body. This new breakthrough with CRISPR can be used to help change treatment, and detect and prevent disease in those who fall ill.

Sources:

 1       1. https://www.sciencedaily.com/releases/2016/11/161108112133.htm#

New gene-editing enzyme, NgAgo, proving to be difficult replicate in lab

There are reports that a new enzyme can edit genes, but no one has been able to replicate the original experiment.

Extraordinary research that shows promise in altering mammalian DNA more efficiently than CRISPR-Cas9, but after multiple attempts, no one can recreate the experiment? What gives? There is a lot of speculation, but mostly complaints as to why researchers failed to replicate it.

There have been many controversial reports as to what the possible role of NgAgo is, but none of them involve editing of genes. One theory was that NgAgo was thought to clamp onto a gene and limit it's expression, noted in the experiment on eye development in zebrafish, but this were correct, the enzyme would not permanently change gene function that's passed down every generation.

Another theory was that temperature could play a key aspect to a successful experiment. The original experiment was carried out in a cool environment, which allows the bacteria, that makes the protein, lives.

Whether this protein's role is entirely different than what the original report says it is, needs to be kept in a cool environment, or just simply doesn't work, the debate surrounding this experiment is insane. Until the NgAgo experiment is published, we will never know whether this enzyme is used for gene editing.

First Clinical Trial in Humans Using CRISPR Gene-Editing

In recent years, many treatments for cancer have involved using patients' own immune systems to fight cancer. A substantial part of these treatments have involved editing the genes of immune cells. Gene-editing has been very successful in fighting not only cancer, but other diseases as well. CRISPR-Cas9 is the most efficient and economical of all gene-editing tools currently being utilized. CRISPR-Cas9 contains a piece of RNA and an enzyme called Cas9, that together can "edit" or change DNA. The first clinical trial for humans, using the CRISPR gene-editing technique, was approved by a hospital ethics board in China this past summer. A team of scientists under the leadership of Lu You, an oncologist at Sichuan University, injected modified immune cells into a patient suffering from lung cancer. CRISPR-Cas9 was used to modify the immune cells of the patients blood, so that the cells attack the cancer by disabling a certain gene that codes for the protein PD-1.

http://scienceblog.cancerresearchuk.org/2016/02/01/crispr-gene-editing-new-chapter-in-cancer-research-or-blot-in-the-ethical-copybook/

These clinical studies are extremely beneficial because if successful, they could provide us with insight as to how well modified immune cells can attack different kinds of cancers, while using a gene-editing technique that is more simple and efficient than others. This article states that the first clinical trial in China could initiate a sort of "biomedical duel" between China and the United States, as they often compete with each other in the advancement of all types of technology. The prospect of this "biomedical duel" is exciting because this type of competition may facilitate quicker progress in cancer treatment research. In the United States the first CRISPR clinical trial is expected to start in the beginning of 2017, as well as more clinical trials in China. I think that this type of progression gives hope to many cancer patients and other people suffering from diseases that could benefit from gene modification treatments.


http://www.yourgenome.org/facts/what-is-crispr-cas9

http://www.nature.com/news/crispr-gene-editing-tested-in-a-person-for-the-first-time-1.20988?WT.mc_id=FBK_NA_1611_FHNEWSCRISPRTESTED_PORTFOLIO